Consistency, consistency, consistency! That and eating to satiety on your eating days and not going overboard, which is easy to do the first couple of rounds. Once you get into a groove it’s pretty simple. No matter how you’re doing mentally or physically, you can eat tomorrow… Just tell yourself that 😀 (Unless sick, of course. Normal guidelines apply re: when to break, etc.)
You need to use all your energy to complete day 1. It’s easy from there on.
Don’t demonize what you eat too: of course eat healthy, but if you slip up… You’re fasting. It makes up for it if you stick to it.