open plaid button down with a slouchy, untucked white tee and dark skinny jeans. I like the hat, but I'd probably wear a beanie or a baseball cap instead. The purse isn't bad, I'd go with one that didn't have a chain strap. Comfy, casual, tomboy
The long cardigan and boyfriend jeans could easily look messy instead of cool...the key is to wear the slimmest of boyfriend jeans so that you don't get swallowed up in all the fabric of the outfit. It also helps if the T shirt is cut close to the body.