Be specific at your goals, be clear on what you want achieve and how to achieve them. By this your aim gets more clarity and you need to only focus on that alone.

Keep everything simple, success grows as you build small, easy habits into larger goals.

Use what you already do. If you get a new habit whixh connects to what you do already, it's easier to keep up with it.

Change your surroundings for better success. Avoid those tempting items such as junk foods for a healthier environment.

You need to know that it's okay if you feel down when things don't go as you have planned. Making new habits is hard. If you miss a day, no big deal, just try not to miss out on two days in a row.

Source: https://www.psychologs.com/web-stories/5-affective-ways-to-develop-positive-habits-in-your-everyday-life/