I do it every day to some extent.. what kind of fast are you thinking of doing?
Coffee with double cream is my crutch.. tea with cream might be a bit more filling?
Orange juice I would suggest avoiding .. maybe sparkling water would be better.
Ease yourself into it maybe just miss a meal ( I dropped breakfast and replaced it with the coffee) then increased my non eating period more and more each day then went to 24 then 48 the 72 hour fasts eventually ending up at 7 days (although not regularly and not for a few years).
It gets easier the more you do it.