The following lines in Yoga Vasistha explains about the Lord or God to be worshiped and best method of worship
VASISTHA: "... Pray enlighten me. What is the method of
worshipping the Lord which destroys all sins and promotes all
auspiciousness?"
SIVA : "Do you know who 'god' is? God is not Visnu, Siva or
Brahma; not the wind, the sun or the moon;
not the priest (brahmana) or the king; not I nor you; not Lakshmi or the
mind (intellect). God is without form and undivided (not in the objects); that splendour which is not
made and which has neither beginning nor end is known as god or lord
Siva which is pure consciousness. That alone is to be worshipped; and
that alone is all.
If one is unable to worship this Siva then he is encouraged to
worship the form. The latter yields finite results but the former
bestows infinite bliss. He who ignores the infinite and is devoted to
the finite abandons a diamond and seeks a peanut. However, the realized
sages sometimes worship a form playfully.
The worship of that Lord is true worship, and by that worship one attains everything. He is undivided and indivisible, non-dual and neither fashioned nor created by activity; he is not attained by external efforts. His adoration is the fountain-source of joy.
The external worship of a form is prescribed only for those whose intelligence has not awakened, and who are immature like little boys. When one does not have self-control, he uses flowers in worship; such worship is futile, even as adoring the self in an external form is futile. However, these immature devotees derive satisfaction by worshiping an object created by themselves; they may even earn worthless rewards from such worship.
Meditation alone is true worship. Hence one should constantly worship the Lord of the three worlds by means of Meditation. The Lord is to be worshiped by one's own consciousness, not by material substances - by waving lamps, lighting incense, offering flowers or even food or sandal-paste. He is attained without the least effort; he is worshiped by self-realization alone. This is supreme meditation, this is supreme worship; the continuous and unbroken awareness of the indwelling presence, inner light or consciousness. While doing whatever one is doing - seeing, hearing, touching, smelling, eating, moving, sleeping, breathing or talking- one should realize one's essential nature as pure consciousness. Thus one attains liberation.
Meditation is the offering, meditation is the water offered to the deity to wash his hands and feet, self-knowledge gained through meditation is the flower - indeed all these are directed towards meditation. The self is not realized by any means other than meditation.
Source : Yoga Vasistha