I find that for myself a huge thing is extensive planning.

It’s easy to be doing something and realize oh I need this and that and then you dig more and more and suddenly scope creep hits and oh man there’s too much now, let me take a break and then never come back.

Sit down with some paper or a tablet and draw out every detail of the game. Explain every mechanic, every state machine, every object placement. If you can design a tightly nit system and all the specific tasks it takes to get there before you jump in, it’ll be easy to implement, you’ll do it quicker, and you won’t feel burned out.