I’d say it depends entirely on what your fasting goal is(as in, hrs fasting). If it’s longer fasts, ease back in. I was doing 18 hr fasts and then tried a 72 hr fast. Terrible.
I’d start with 18 for a couple of weeks, then maybe transition to 36s, then 42s, then 60-72-depending on where you want to end, of course. Just take it slow.
And mind your electrolytes! Good luck, it’s easier when you have a partner.