Make everything as easy for future you as possible. This might sound silly but it’s all about harnessing current time and energy and distributing it to future you who will be tired/lazy. For example, I make breakfast the night before so that in the morning it’s not as hard to get up at regimented times and start my day. I signed up for a gym that I have to walk past to go to work so I have no excuse not to go in. I’ll block my calendar out weeks in advance so I know exactly when I should be doing personal work/not.
Lowering the barrier was the only thing I found that helps me stay strict to the lifestyle I wanted. Otherwise it was way too easy for me to blow it all off.