When I was around 10, I gave up thumb-sucking. My parents had tried to talk or trick me into forsaking the activity for as long as I could remember, but it was fear of peers that inspired me. I was allowed to spend the night at a friend’s house by then, and I was too embarrassed about the habit to continue it.

When I was around 12 I stopped biting my fingernails. Again my parents had tried and failed, especially Mom and even to the point of painting on some vile-tasting “polish” (she glopped the tan-colored stuff on so thickly that it was quite easy for me to pick it off). I gave up the habit because I was becoming more style-conscious, and I loathed the look of fingertips bulging above bitten nails.

As I matured I acquired other undesirable habits, like escape into dietary binges, excessive consumption of chewing gum and soda, cigarettes, inactivity. I’ve managed to cure myself of those, a practice that is now called behavior modification. And here’s what I have to say about how to do it.

First off, know yourself. No How-To manual can tell you what you know best: your own self, what motivates you, what you fear, how you are.

Next, make time. You’re probably already fully occupied so the moments you’ll need for this work must be reserved (I love it when I answer the phone and my caller asks if I was doing anything…how not? I don’t know anyone who just sits there waiting for the phone to ring).

Now map your campaign. Breaking an old habit or forming a new one is similar to a military plan; it requires a strategy (which is the overall path, the part set by the general before the action starts) and also tactics (the responses in the field, to whatever obstacle or opportunity presents itself). At the least, the strategy arranges the time for work and the tactics describe the feedback.

Finally, build in some room for grief. Because the truth is, a habit is a very close friend, and losing a close friend is a grievous experience. It may take only 6 weeks to form a new habit, but it will take a full year to process the grief about what you gave up.