Gentleman with 11 years of experience here.
I would take a sildenafil to make it memorable and a good experience, but if you haven't tried it before, start with 50 mg - 30 minutes before your session. Also, how long is your session?
Drink plenty of water before the session, regardless if you do take sildenafil or not, the water calms down the body.
Really good advice. When I started seeing companions I used to be nervous worrying about performance and would let it get in my own head but I started researching things that help improve sexual performance and these are my tips that have helped me:
1) Getting exercise during the week helps your testosterone. If you eat poor AND dont get any exercise, it can & will affect you in bed.
2) Drinking alot of water during the day is a really good one as you suggest. Hydration helps everything.
3) Do NOT eat a big meal before seeing someone. Preferably dont eat at all in the hours before your session depending on when it is.
4) Taking vitamins regularly helps too. I take TongKat Ali, Zinc, Vitamin D, L-Argenine and Ashwaganda. Helps erections & performance
5) I take Taladafil an hour before every session