Any formulae or snippets you use often, have them ready to go and organised.
Things like:
- Player controllers
- Simple event triggers and loops
- Setup/housekeeping code
Having a checklist of reusable items or things to look after in each project will save you time knocking those out so you don't forget.
You can always look at past projects (if you have any) to see what problems you've had to solve, and how you approached them.
If find layout can sometimes fool you into taking loads more time than it ought.