really this is also my second fast nursing. I decided to buy formula and just not nurse after the morning-it was much easier. When I nurse I get so thirsty so I think for YK its just better to not risk it
Drink drink drink from 3 days before. Not just water, but electrolyte drinks (Powerade, Gatorade, vitamin water). Got this tip on this website and it's made all the difference for me when I nurse.
Backup bottles/formula are also helpful. Don't wait till you're dehydrated.