1) With 2 shooters, make sure all the cameras have the same date and time
2) For difficult lighting like bright afternoon sun, shoot RAW to have the range to handle exposure diversity
3) Shoot in manual and use the handheld meter
4) Preset white balance on every set
5) Don't use the lens hood for the wide angle lenses
6) Bounce the flash, don't set it direct because the lighting is dull and the angle is too low
7) Don't shoot while people are eating, wait for the tables to be cleared off, and ask people to look, not candid group
8) Arrange groups in a straight arc, but consider tiers with diagonals and triangles
For 2 or 3 levels, shoot down onto the group to have better depth of field
9) Let guests take their shots first, then take yours; observe while they shoot
10) Use more depth of field to get all objects on the table in focus
11) For shooting in direct sun on the subject, setup a scrim