When you rifle through the the lighter layers in your closet — don't bypass your jean jacket. It might have been a middle-school staple for years, but for about a million reasons, it's still a perennial fixture in our closets, providing just enough warmth and just enough of a cool factor.
If, however, you're a little rusty on styling your favorite denim jacket, we've tapped a few style stars to help inspire some new outfits. To take you from early Spring right through Summer, just look to Mandy Moore , Kate Mara, and Jessica Alba 's clever ways to style a classic. Scroll through for all the outfit ideas now.
Source: Getty/Michael Kovac 
Kate Mara did the dressed-up version of denim on denim, adding a jean jacket to a little jean dress at the Louis Vuitton Fall '14 show.
Nikki Reed  played leather pants against her denim jacket for a cool effect at the People StyleWatch Denim Awards in September 2013.
Mandy Moore 's denim-jacket styling trick? Add it to a sophisticated pencil skirt and pretty top to give the look a more casual vibe.
We love how Emmy Rossum's denim jacket lent laid-back flair to her flirty accordion-pleated skirt and floral Rebecca Minkoff bag in LA.
Amy Adams  got ready to take off in double the denim. She started with skinny jeans, then added a lighter denim jacket for further cool.
AtCoachella in 2013, Jamie Chung made a concert-cool pairing with her Levi's denim jacket and floral minidress.
Hailee Steinfeld created the perfect Summer travel ensemble in her denim jacket, printed maxi dress, Ray-Ban Wayfarers, a bright red bag, and black patent flip-flops.
January Jones  took a casual red carpet approach in a cropped denim jacket, which she wore over a white sheer blouse, black leather pants, and black peep-toe booties.
Rosie Huntington-Whiteley gave her cutout heels and draped maxi skirt a dressed-down finish with a staple denim jacket.
Gwen Stefani  was slick in a leather-sleeved denim jacket by Paige Premium Denim, matching black leather baggy jeans, a baseball tee, and high-top sneakers.
Jessica Alba  perfected denim on denim, adding a faded jean jacket to floral bottoms while out in LA.
Julianne Moore took her denim jacket on an avant-garde ride by pairing it with gray trousers featuring a dramatic pleated waist.
Natalie Portman  juxtaposed a dark denim jacket and white jeans while hanging out with son Aleph in LA. A printed scarf broke up the look, while Westward Leaning sunglasses injected further cool.
We're not surprised that Cara Delevingne spruced up — and edged up — her vintage denim jacket with black tape, not to mention striped leggings, turquoise sunglasses, and high-top sneakers.
Molly Sims tempered her busy floral maxi dress with a denim jacket at a Baby2Baby event in LA.
Elsa Pataky exuded a sporty aesthetic in a black tank dress, high-top sneakers, and a denim jacket while hitting the streets of Beverly Hills.
On another occasion, Emmy Rossum gave her Tory Burch Ramona dress  ($450) a kick-back air via a denim jacket, then added a blue structured crossbody bag and green ankle-strap sandals for further oomph.
Shop our favorite denim jackets below: