The way I do my own theme system is like this.

I look at my previous theme and think about putting into words how I want to improve over the next three months.

Then I try to find 5-10 outcomes to make that happen.

After that I do what I call a “sub-theme”; and that is a 1-2 week period where I have one goal and one action per outcome. Where the idea is that I try to move them forward every day by doing something.

At the end of a theme or sub-theme I do a retrospective and use that to influence what I’ll do next.