If you are following the Gaudiya Vashnava line.

Firstly, Radha Krishna and the acharyas must have their own plates.

Then say the mantra below, short and sweet.

First offer food and drinks to Krishna

For food say 'etat sa tulasI naivedyam sri krsnAya nivedayAmi namah
For drinks say 'etat sa tulasI pAnIyam gangodakam sri krsnAya nivedayAmi namah'

2nd part of the offering is to Radha and sakhis
say 'Sri RAdhikAdi sakhI-ganebhyo namah'

3rd part of the offering is to Sri Gurudeva
say 'Sri GurudevAya namah'

After that I say the Hare Krishna Mantra 2 times and then leave them to enjoy their meals