Set totally outlandish goals to accomplish in a ridiculously short timeframe. Then follow these steps:
1. Start with a hearty love of all things food.
2. Rather than cease food consumption when full, harbor a tendency to overindulge due to "deliciosity" or desire to "not be a waster".
3. Have a particular weakness for, and inability to refuse: pie, cake, cookies, candy, bread, pasta with thick creamy sauces, etc.
4. Tell yourself that your body "just isn't ready" to workout. If this is actually true due to illness, injury, or a medical condition (like a c-section), continue using this reasoning far beyond it's validity.
5. When beginning a new exercise routine, tell yourself it's "ok to take it slow". (if you plan to work hard, then on the days you slack off, at least you just take it slow. But, if you plan to take it slow, when you slack, you're basically then doing nothing.)
6. Be diligent with exercising for the first 6 weeks of the 9 week program, then in the 7th week, get really busy and allow yourself to "fall off the wagon".
7. To aid in the accomplishment of #6, rationalize on a daily basis a current or impending weather condition that prevents you from doing your outdoor exercises: too hot/cold, too windy, too sunny, possibility of precipitation, etc. To utilize this tactic even further, use the baby as a scapegoat: "too hot/cold/windy/etc. for the baby."
8. Buy an exercise DVD for days you do #7. Leave it in the wrapper... Indefinitely.
9. Go grocery shopping at sam's, have every intention to only select healthy items. End up purchasing a 5 pound bag of reece's peanut butter eggs, or other seasonal junk food. Put apples and other healthy snack choices in the back seat, scarf peanut butter eggs all the way home "before they melt".
10. Eat before bed or during the night because "nursing the baby so often makes me really hungry!" If this is actually true for you, refer to #2.
Then repeat... :)