At least 40% of what you do everyday is a habit. Some of those habits are good for you and some are bad. The majority of those habits just developed without conscious thought however. Once a year it is a good idea to take a habits inventory. Sit down for half an hour and list all the habits you are aware of. Because you do these habits subconsciously it can be hard to think of them at first. Every habitual action starts with a trigger. So don't start looking for the habits when you sit down to make your habits inventory, start by looking for the triggers. Triggers are things like previous actions, alarms, times of day. For example when I go to the bathroom to get ready in the morning I floss my teeth, I brush teeth, I get in the shower, I get washed in the shower, I shave... Always in that order. Its my habit.
Once you have your list of habits, evaluate which ones are good and which ones you should change. Then pick just one habit to focus on for the next month and work on that.