The last few months I've had trouble starting work on my game. Sometimes I'd procrastinate until early evening and then do only an hour of gamedev if that.
So I started rewarding myself for starting work by having a brownie or a muffin or whatever I feel like eating but I shouldn't because of soul crushing gymcel diet.
And it's been working for a week so far. Now I start working right after breakfast. It's like a little ritual: I sit down, open the IDE, write down what I'm supposed to do that day and eat the brownie. I think I've associated the pleasant feeling of eating sweets with work.
So if you're procrastinating try rewarding yourself for getting to work with something you enjoy but otherwise voluntarily abstain from. Obviously food won't work if you eat whatever you want whenever you want.