B and D

Here's the most helpful thing I learned as a summer associate at a law firm.  When I went out to lunch on my first day with a bunch of scary partners and a few other summer associates who were just as scared as I was (even though they all appeared to bluff their way through it with far more aplomb than I!), we all sat down at a round table and there was the inevitable and awkward chorus of "Is that yours/I think this is mine/whoops, I may have taken a sip out of your water, sorry!"

image via this fascinating article about how to dine Downton-style

One of the partners taught us all a little trick that I've used countless times since: 

image via here

When you sit at the table, make a circle with your thumb and pointer finger on each hand. 

Your left hand makes a lowercase "b" shape, and your right hand makes a lowercase "d" shape, which will remind you that your bread plate is on your left and your drink is on your right. 

Bon appetit!