One of my favorites ways to layer during the spring is with a classic denim jacket or vest  under instead of over. In years past, I have layered a denim vest under a blazer and this season, definitely loving it under a trench. Having that denim peek out from under another jacket is a bit unexpected and adds a touch of boyish charm that I love.

Always reliable are  J.Crew,  Madewell,  Gap and Old Navy.