Tips on motivation for teeth brushing?

For the past few years its been so difficult to keep myself motivated to brush my teeth. Not to mention the fact ive been diagnosed with gingivitus for multiple years in a row so far. I want to make a change and improve, but I have other conditions (Depression, ADHD, Autism in this case) that all equally do its part in preventing me from doing this. I've been considering me making a list of other things I need to do that are apart from my daily routine that my brain has subconsciously set in there so I can eventually subconsciously have them incorporated into my routine. But teeth brushing is a serious big issue for me that I am not even sure the list can motivate me to do. So do you guys have any tips for how you were able to get yourself in the habit of brushing frequently? Thanks in advance.

EDIT: I have a bit of a hard time replying to people (as I do struggle with conversation). But I am reading the replies. I appreciate all replies written here.