I started with reading a lot of self help books regarding habits and systems for making things easier. Then I started implementing some.
The Bullet Journaling Method - helped me consistently make a daily to do list so I could focus on what to do daily, as well as collections that help me keep track of things such as my reading list and what's next.
The Getting Things Done system - helped me get more of my to do's done in a master system according to priority and location. It helped declutter my mind.
Tiny Habits - helped me get some super easy new habits implemented such as immediately empty my bag after I come home and putting away dishes after eating, and am attempting to use it for harder habits as well.
I found that different things work for different people. Someone who prefers everything digital might not like the bullet journaling method, for example. Or they do, in a digital way. Sometimes I find that a habit gets fixed just by finding that one tip by someone else, a book, or website, that is the perfect solution for me. I think it's part understanding how to make habits work, but also part finding the right system or process that works for you. Some things are instant and some take a long time to implement. Bullet journaling took me 2 years to get into a habit of doing it daily, as well as finding what works for me. I'm still getting used to the Getting Things Done system and have re-adjusted it several times. But it has helped me so much to find different things to try out.
