Vishnu pooja is normally done during one’s planetary positions are not favourable for gaining peace in our life.  It is a simple ritual that can be done during one’s birth star by a SwastikPadmam and a lamp.  This is done in the morning.  VishnuSahasraNamam, Purusha-Sooktham, NarayanaSooktham and the like are used during this Pooja.  DvadasaNamam, AshtotharaSatham are also used for Pushpanjali. Palpayasam (Milk Pudding) is the main offering.
The same pooja is done with elaborate rituals such as KaluKazhikichUttu (ritualistic offering to a Brahmin) on special occasions like 60th (or 70th / 84th / 90th) birthdays.  When Vishnu Pooja is done on monthly birth-star days and this elaborate one is done on birthdays during the unfavourable planetary positions, it is found to be very effective.  The blessing from the Brahmin during the ritualistic Pooja is considered very auspicious.
Similarly, auspicious and prosperity is prayed for when Lakshmi Pooja is done, Saraswati Pooja for better education, Sukrutha Homam for ancestral blessing and KarmaDosham, Sayoojya Pooja for a blissful life are some of the types of Thantric rituals for the improvement of our life on earth.....