I time it so I start the fast towards the evening and then it ends mid-morning - so you're only really pushing through one full day without food.

I'll have coffee/tea for caffeine and electrolytes seem to help depending on your situation.

Start with several smaller fasts before going full 36 and if you need to eat before the full 36 hours are up, don't kill yourself.

The biggest realization is just coming to terms with how much what a lot of people think of as "hunger" is often just boredom or cravings and not actual hunger. That was eye-opening.