After searching multiple Parisian fashion guides, including Conde Nast’s “What to Wear in Paris, According to French Fashion Designer Jeanne Damas,” I decided my best move would be to find a good pair of jeans or a pair of comfortable cargos with an oversized sweater. So, I decided to venture out into Boston to find a new pair of “go-to” traveling pants.

What can people do with old jeans? Throw them away? Donate them? There never seemed to be a good solution, until now. This fall, the denim-focused clothing store Madewell teamed up with Blue Jeans Go...