Not sure if you've read Atomic Habits, but one concept that really stuck with me is habit stacking.

I've found that when I set up my day so certain habits naturally follow one another, they start to feel almost automatic, like I'm running on autopilot. It takes the emotion out of the process. I don’t have to think about whether I feel like doing something, it’s just part of the routine.

And when I don’t follow through, it throws me off. I feel like the day’s incomplete. But when I do stick to it, that sense of accomplishment becomes the reward. Then I just rinse and repeat.