The most general verb to use with habit is have, "He has a lot of bad habits." Because it's so general, however, you can substitute in a variety of other verbs for varied effect. Consider these quotes:
The truth is that everyone is bored, and devotes himself to cultivating habits. ― Albert Camus
A man who can't bear to share his habits is a man who needs to quit them. ― Stephen King
Statistics show that of those who contract the habit of eating, very few survive. ― George Bernard Shaw
I wanted to be a brain surgeon, but I had a bad habit of dropping things. ― Gilbert Gottfried
One has to grow up with good talk in order to form the habit of it. ― Helen Hayes
And many more. In your example, much depends on whether you're going for humor, advice, observation, or something else. Some possibilities: practice, express, indulge, nurse, embrace, etc.
If you get rid of the "in moderation" then you can simply moderate a habit, or manage, repress, conceal, keep, nurture, etc.