Water

Seriously, always have at least a tall glass of water after a session. You lose more than you think.

I drink water throughout my scenes. All the moving around and talking and I get thirsty!

I've been asked to drink wine or other alcohol with a client and I always decline. The last thing I want to feel when I'm trying to be in control and safe is intoxicated.

I've been appreciating water in a new way the last week.

I got badly dehydrated trying a new ( to me ) allergy drug.

Everything tasted salty. I couldn't tolerate drinking too much at a time. Using better tasting filtered or chilled water really helped.

Pretty important to drink water (not just "recycled" water) during session.

Throughout my normal days I only drink water, seltzer or black coffee. However, during session I always have some drink with sugar (e.g. snapple, arizona etc). I find it helps with the lightheadedness that can set in halfway through an intense session so that I can rally.

I hear what you are saying and agree. However, I remember one time going to the Olde English Chamber in Philly. 15 years ago. Set appt. for 7. Told not to be late, or early. Receptionist said if you get here early head to the bar next door and have a drink.
I got there early and went and had a lemon drop shooter and a beer. I was relaxed the whole session and things opened up better.
I certainly wasn’t drunk but felt great and the session went great.