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A little more than a year after having her third daughter, Angie Harmon is finally happy with her body again, although she admits that getting back into shape gets tougher every time. “I’ve had to actually work out and drink a ton of water and be conscientious of what I eat and things like that, where I didn’t have to before,” the former Law and Order actress tells PEOPLE behind-the-scenes of her new Olay Pro X commercial in Encino, Calif. “Every time you have a baby, the weight disperses in different places and you come out with a new, not necessarily improved, but just new body.” Harmon, who is married to former NFL star Jason Sehorn, credits her slimmed-down shape to eating right and staying hydrated — and says patience has helped, too. “As you put it on in trimesters or every three months, it comes off in trimesters,” she says. “It takes about a year to lose everything that you put on, in my opinion.” Harmon prefers to do her cardio by biking or walking, and instead of lifting weights lifts “children instead.” In terms of diet, she watches what she eats, although she confesses, “God, I love a Junior Mint.” Overall, she also admits to being “lazier” since her 13-month-old daughter, Emery Hope, was born, saying it takes more effort to work out. However, Harmon suspects the arrival of bathing suit season will “definitely motivate me to get off the couch.” One place she’s definitely not lacking motivation these days is in her skin care regimen. “They asked me to do this [Olay Professional Pro-X] 28-day challenge and I was like, ‘err… okay’ — so convinced that I was going to break out and not be pleased and then have to fix everything by getting back on my normal regimen and all that,” she says. “But it didn’t work out that way at all. It was really, really great. Their wrinkle treatment I now have in my permanent regimen (not that I have wrinkles!).” She was so pleased, in fact, that she agreed to shoot a promotional spot for the product. But aside from skin care, when it comes to staying gorgeous, there’s one item she never leaves the house without: “Always, always lip-gloss,” she tells PEOPLE. “I’m obsessed right now with a roller ball lip-gloss. Obsessed! It’s just a strawberries and cream one — it doesn’t even say what brand it is. Love it!” –Pearl Barraclough and Blane Bachelor