Here's a great plaid shirt by BB Dakota with flattering 3/4-length sleeves and a nipped waist in a soothing forest green hue, just $44 at chickdowntown.com. You can wear it now layered over a tank with shorts, then again in the fall with jeans and boots.
Need another option? This buffalo plaid shirt is one of the cuter items I spotted in the newly released Miley Cyrus & Max Azria clothing line for Walmart. Keep in mind the sizing is juniors, but I think this top would work for many ages. It's just $12 and also comes in red plaid or purple plaid. Check out the rest of the collection here, especially if you're in back-to-school shopping mode.