Poojaa or worship is of two types - Nish-Kaam and Sa-Kaam. Nish-Kaam Poojaa is done without any desire and Sa-Kaam Poojaa is done to fulfill some wish. When a Poojaa is done with some desire, its fruit depends on the simplicity and complexity of the Pojaa done. For example, if somebody does Poojaa with the desire of some specific situation or thing, if the fruit is hindered by some previous life's Karm strongly, then one doesn't get its fruit by doing Poojaa only one time. One has to do it several times.

But today's people don't have so much patience and lose their patience and as a result they lose even the belief in Devtaa. It is not good. It may harm instead of benefiting. In fact the same Sa-Kaam Poojaa is successful which is done methodically with the complete Shraddhaa in Karm, Devtaa and its fruit. Thus both, method and Shraddhaa, are necessary to get desire fruit.
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Bhagavaan's worship is said to be of five types - Abhigaman, Upaadaan, Yog, Swaadhyaaya (self-study), and Ijyaa. Cleaning Bhagavaan's place is called "Abhigaman". Gathering flowers and sandalwood paste etc things is called "Upaadaan". My Isht Dev is not different from me - this feeling is called "Yog". To do Jap by understanding the meaning of one's Isht Dev's Mantra is called "Swaadhyaaya". Reading Sookt, or Stotra, doing Bhagavaan's Keertan, studying Shaastra etc also come under "Swaadhyaaya". To worship one's Isht Dev methodically is called "Ijyaa". They give Saarshti, Saameepya, Saalokya, Saayujya and Saaroopya named Mukti respectively."
[Padm Puraan, 4/17]
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Another division is - Aaturee, Sautikee, Traasee, Saadhanaabhaavinee, and Daurbodhee.

(1) Aaturee Poojaa - A patient should neither take bath, nor do Jap, nor worship. He should do only Darshan of his Isht Dev (idol, or Soorya's Darshan), remember his Mantra and offer flowers. When he becomes all right, then he should take bath, salute his Guru and pray that "By the grace of your Prasaad, I should not be blamed to abandon Poojaa." After taking his blessings he should resume his Poojaa. Feed Braahman and give Dakshinaa. 
(2) Sautikee Poojaa - Sootak is of two types - Jaat Sootak Sootak) and Mrit Sootak (Paatak). In both kinds of Sootak, one should do only mental worship. After Sootak is over, one can resume normal worship after taking blessings of Guru and Braahman.
(3) Traasee Poojaa - Who has been afflicted by his enemies, he should do worship with whatever is available to him or even mentally.
(4) Saadhanaa Bhaavinee Poojaa - When one cannot get Poojaa materials and does Poojaa only with available leaves, flower or fruits; or mentally, it is called Saadhanaa Bhaavinee Poojaa. 
(5) Daurbodhee Poojaa - A woman, an old man, a child and a fool worship in whatever way because of their A-Gyaan (ignorance), that is called Daurbodhee Poojaa.
(Naarad Puraan, p 431-432)
(Bhaagvat Puraan, 11/26)

Maanas Poojaa
Maanasik Poojaa , is a Poojaa in which you require nothing but your imagination. You visualise the Poojaa. It may be simple or elaborate. It can take place at any exotic location. And you can use the most exorbitant ingredients, as you have to pay for them in terms of only your faith and love. The advantage of a Maanasik Poojaa is that your mind cannot wander. The Scriptures promise the same rewards for this Imaginary form of worship Try the above Poojaa anytime that you are on a flight of fancy, or literal.

Now for the conventional Poojaa:
Keep your house clean and draw a Rangolee at your doorstep to welcome Goddess Lakshmee
For the best time for Poojaa, a Pandit could be consulted.
You will require:
Some silver and gold coins.
10 Suparee (whole betel nuts)
Some uncooked Rice
5 paan leaves
A coconut
Water in the 'Lota' (for Kalash). May add Ganga water if you have.
Kumkum for applying Tilak
Gulaal (Holee color)
Mithaai (Indian sweets)
Flowers
Agarbattee(incense sticks)
Diyaa
Camphor

--On a new piece of cloth, make mounds of rice and place Supaaree on top. The Supaaree stand for the planets. Either keep another Supaaree for Ganesh, or a Ganesh icon.
--Fill the Lotaa with water, adorn Paan leaves around the Lotaa .Place a coconut on top of the Lotaa.
--Dress the Lotaa with a red cloth and tie a red string around it. On the Lotaa draw with Kumkum four lines representing the Ved. A Swaastik moving clockwise with 4 Teekaa. Light the Agarbattee and the Diyaa.
--On a Thaalee place the silver and golden coins. These represent 'wealth' or Lakshmee.
--Take some water on your left hand and sprinkle water on to yourself after washing and purifying your hands.
--Place a flower on your palm with some rice.
--Chant the Gayatri Mantra 3 times (optional).

--Now first visualize Lord Ganesh. Welcome Him to your Poojaa. Chant a Ganesh Mantra. If you are not very good at remembering Mantra, let me make it easier for you. Say: Om Ganeshaya Namah or I bow to you Lord Ganesh
--Pray to Shiv Jee the same way. Say: Om Namah Shivaaya
--For the more enthusiastic ones, please refer to 'Mantra and Prayers' for more Mantra / prayers for Ganesh or Shiv Jee
--Sprinkle water on the Lotaa, apply Kumkum, shower rice, offer a Mithaai and fruit and accord the same treatment that you would to an esteemed guest. The water in the Lotaa stands for all the sacred rivers.
--Follow the same procedure with the 9 planets and the 4 directions. Sprinkle water towards the North, South, East and West. These are the 4 'Dishaa' of the world or the Universe.
--Then bathe the silver and gold coins with milk, water, Gulaal, flowers and offer the Mithaai. It is said if you make the coins jingle, it would attract Lakshmee Maa to come to you.
--Visualise Mahaa Lakshmee and say: Om Shreem Mahaa Lakshmyai Namah

Now you are ready for the Aaratee. Light the Aaaratee Diyaa. Light camphor. Sing the Lakshmee Aaratee to the tune of 'Om Jai Jagdeesh Hare' along with the accompaniment of the jingle of the bell.
Then place the Thaalee in your safe for 3 days.
--Do the above with faith and devotion and don't worry too much if you do not do it very correctly.
--Say 'Haraye Namaha' 3 times. That takes care of all the mistakes that you may have committed knowingly or unknowingly during the ritual.
What is most important is your faith and love.

--What kinds of flowers? The ideal would be the offering of ones ego, attachments and obsessions.
Eight types of flowers can be offered to God, namely
(1) Ahinsaa (Non-violence),
(2) Indriya Nigraha (Control of senses),
(3) Sarvabhoot Dhaaya (Compassion towards all beings),
(4) Satyam (Truth),
(5) Dhyaan (Meditation),
(6) Shaanti (Peace),
(7) Vinaya (Humility),
(8) Bhakti (Devotion).

How to Worship
Naarad Jee said - Now I tell you the method of Vishnu's worship - This worship is of three types - Vaidik, Taantrik and mixed. One should worship Him with all three methods. Vaidik and mixed methods are prescribed for all three Varn - Braahman, Kshatriya and Vaishya, but Taantrrik worship is prescribed only for Shoodra. Bhagavaan's idol is of eight types - of stone, of metal, of iron, of clay, picture, of sand, Manomayee (as one likes), and of gems. These idols are established with two methods - movable and immovable.

Bhakt should worship Him with whatever is easily available to him. In idol worship giving it bath and ornaments (flowers) are all right (means just give it a bath and offer flowers). Offering even water is good. Gather all worship materials and sit on a Kush Aasan facing north or towards the idol. Draw an 8-petal lotus flower and establish the idol on it. Give it a bath, the clothe it nd adorn it by flowers, etc. Offer Naivedya (jaggery, Kheer, Ghee, Pooree, Maalpooaa, Laddoo, milk, yogurt etc). After worship one should do Dhyaan and finish the Poojaa. One may do Havan also with Havishya Ann. One should touch his head with offered flower or flower garland. After the Poojaa is finished, if the idol is for Visarjan, one should do its Visarjan too. This is Vaidik and Taantrik Poojaa of Bhagavaan.
[Padm Puraan, 4/20]

People worship in several ways - 
(1) Panchopachaar Poojaa - Worship done by five articles, normally by water, flowers, incense, flame of a candle or Ghee lamp and an offering of sweets is called Panchopachaar Poojaa
(2) Shodashopachaar Poojaa - Worship done by 16 articles, normally by water, flowers, incense, flame of a candle or Ghee lamp, sweets, red vermilion, rice etc is called Shodashopachaar Poojaa. Symbolically it is done by five elements, the ten senses, and the mind.
(3) Mental Worship - In mental worship the Panchopachaar Poojaa articles are replaced by the five gross elements of earth, water fire, air and space along with their corresponding subtle energies.

Poojaa Materials
There are normally 16 materials to worship (Shodashopachaar) our Deity with, but the following are normally must - Rolee (or Haldee - turmeric powder); rice, flower, sandalwood paste, lamp, incense sticks, Dhoop (sweet smelling material to burn), and Naivedya (food to offer - sweets, or fruits, or dry fruits), and Panchaamrit. If it is Vishnu Poojaa, then Tulasee leaves are also must. Optional materials are Paan (betel leaf) etc.
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Yam Raaj said to Braahman - "If one doesn't get flower or leaf, he can worship Him with Ann (cereals etc) - rice, wheat, raw rice with husk (Dhaan), barley etc.
(Padm Puraan, Paataal Khand, p 596)

Panchaayatan Poojaa

Aaadi Shankar evolved a method for harmonizing Shaivites and Vaishnavites. The Isht Devata is kept in the center and the other four Devtaa are placed in the four corners. If Shiv is placed in the center and Vishnu is placed is in Panchaayatan of a square - it becomes Shiv Panchaayatan; if Vishnu is placed in the center and Shiv is placed in the Panchaayatan of the square it becomes the Vishnu Panchaayatan.

The Pauraanik Hinduism has offered a large number of Devataa most of whom did not exist during the Vaidik period. The basic idea that all of them depict the different aspects of the One and the same Supreme God (Parabrahm) persists.

Usually Panchaayatan Poojaa is performed with the following:
Shiv - in Baan Ling form
Vishnu - in Shaaligraam form
Aaditya or Soorya - in clear crystal form
Ganapati - in Son Shilaa form (a reddish stone)
Devee- in a resplendent golden/yellow crystal form (a sulfur compound usually found in black stones used in floors of old houses - not the granite).

Geometrical drawings (Yantra) like square, hexagon or circle etc are also sometimes used to represent these deities. In addition to the symbolic objects mentioned above, the five deities may be worshipped in their images of small size also.

Panchopachaar Poojaa

Panchopachaar Poojaa means worshipping the Deity with five things or elements, it is customary. These five things are - symbolic dedication of (1) Jal (water) (2) Akshat (rice) (3) Pushp (Flowers) (4) Dhoop-deep (incense and lighted lamp) and (5) Naivedya (sweet offering), and keeping them one by one in a dish.

Water is symbolic of modesty and compassion. Rice implies happiness, prosperity and beauty. Dhoop-deep implies spreading light by self-effacement. Naivedya implies sweetness and gentleness of nature. By Panchopachaar worship the Saadhak resolves to equip his personality with righteousness.

There is another version and explanation of five things -
(1) Gandh - fragrance - incense or sandal paste etc, representing Earth element;
(2) Naivedya - food - sweet porridge, fruit etc, representing Water element;
(3) Deep - lamp, representing Fire element;
(4) Dhoop - incense smoke, representing Air element;
(5) Pushp - flower, representing Space element.
These should be offered to the Deity in the beginning and at the end of the worship.

Shadopachaar Poojaa Process

Poojaa's complete process is called Poojaa with Shodashopachaar (Shodash Upachaar - 16 processes to the Deity) - 

(1) Aavaahan - Welcoming the Deity.
(2) Aasan - Offering seat.
(3) Paadya - Washing His feet.
(4) Arghya - washing the hands.
(5) Aachaman - Offering water to drink.
(6) Snaan - Bathing.
(7) Vastra - Offering clothes.
(8) Yagyopaveet - Offering Yagyopaveet - Of the 72,000 Naadee in our body, Sushumnaa Naadee is the most important one as it is through this the Kundalinee Power rises, that is why it is called Brahm. Naadee also. This bestows us with the knowledge of Ultimate Par Brahm. Recognizing this we symbolically we offer a sacred thread to the Deity.
(9) Aabharan - Offering ornaments - Recognizing that we are a part of Divinity and the outer. ornaments we wear are the attachment to Maayaa, by offering our ornaments to the Deity is a symbolic gesture of renouncing the worldly attachments.
(10) Gandh - Offering sandalwood paste.
(11) Pushp - Offering flowers.
(12) Dhoop - Offering perfumed incense.
(13) Deep - Offering lamp or light.
(14) Naivedya - Offering food.
(15) Taambool - Offering betel leaf.
(16) Pradakshinaa Namaskaar - Circumambulation and saluting the Deity.

Poojaa With 32 Materials
A more elaborate Poojaa will be by 32 materials to the Deity -