I agree it’s quite important for us to feed our minds with positivity. The only sort of routine I have for positivity is doing what I enjoy first. That is writing.
Some other things I have heard are things like exercising and even keeping a gratitude journal. I do state gratitudes mentally but not really write them down. Not to mention my exercising is normally a few hours after I wake up rather than immediately.
Still, those things can be worked on and I think doing them could probably help you out in being more positive.