For summer, I recommend their simple maxi dresses. If you're unsure about the look on you - what better way to try it out than with a cheap, non-committal one under $15? The thing about F21's maxis is that they are made for 5'9" models. Look for ones with higher waistlines, so you can do an easy DIY hem or snip.
Click below to shop (all under $15):beaded bib necklace ($7.80). I picked it up here and have been loving it for filling up unsightly spaces caused by low necklines. OOTD's from this weekend:
Theory jacket, F21 belt, BR ruffle dress, Target chambray shirt (all old). H&M circle skirt (current)