Every day I read a newspaper and I read some more pages from my book. That is now a habit.
Habit is not about motivation, it is like cleaning your teeth, you do it out of habit.
I speak to positive people. If negative people try to talk to me I reject them, tough but true. I speak a lot to the same people so we become part of each other's lives, friends who chat weekly, a habit.
I don't write much but when I do, I write simple stuff so I get positive re-enforcement.
When I watch youtube I watch stuff that interests me, make it positive.