Hot mama! After giving birth to Maxwell Drew on May 1, Jessica Simpson has been working hard with her Weight Watchers group, as well as with fitness guru Harley Pasternak, to shed the baby weight -- and it's working! The Fashion Star judge and iVillage guest editor unveiled her post-baby physique during a recent trip to New York City and told iVillage exclusively that she's feeling good in her clothes again, only four months after giving birth. What's her secret? "Every week I set a goal," she tells iVillage. "I think that it's really important to pat ourselves on the back every week -- or even if we don't meet that goal, to go through the frustration of not meeting it, and having it encourage us to work harder next week." She tells us, "This definitely improves your relationship with yourself by making you stronger and more motivated." Get inspired by Jessica and become your biggest fan! Create a weight-loss plan and track your progress week-by-week. Celebrate each pound that you lose and every extra push-up you do. If you slip up, don't be hard on yourself -- use that disappointment to fuel your efforts to reach your next goal.