Factors to consider when choosing a new habit to track:

• Motivation: choose a habit you personally care about. If you pick a habit out of a sense of obligation, your motivation will fade.
• Regularity: find a habit you can track daily. Each habit repetition enforces ...

• Paper: if you use a diary or daily planner, make notes each day if you completed your habit or not. If you do a regular weekly or monthly review, this is a great time to check back through your notes to see how you’re progressing over time.
• Spreadsheet: you can set up a...

The best way to turn a behavior into a habit is to use a trigger to remind yourself to do it. Your trigger needs to be something you always do anyway. Anything you already do without thinking works.

As you build new habits, you create new triggers for yourself and stack a new habit onto it....

You can’t fully focus on any behavior if you try to establish several at once. 

Doing so risks overloading your willpower and your habits may end up competing for priority.