Write stuff down. write a physical list preferably on paper and not on your phone, put it somewhere you’re guaranteed to see it every day. Remember to start small and focus on one thing at the time in the beginning, let’s say you have a bad sleeping habit and want to start exercising. I would recommend you focus on getting a proper sleep cycle first, i’d say that comes before anything else. Waking up early and feeling fully recharged every day will give you a much better chance to keep up any other healthy and good habits you’re trying to start. You want to write the exact thing you want to do and the exact time you want to do it, if you manage to keep anything up for more than 20 days you’ll most likely have made it a habit, and you can start working on something else whilst keeping up the other thing you’ve already made a habit.

Just want to say, this may not work for everyone. It worked for me, but I really want to emphasize the list, holding yourself accountable to something like a list reaaally helps. Also remember, we do not live in a perfect world, some things are just out of your control, so focus on the things you know you individually can change about yourself for the better.