When it comes to effortless summer elegance, you can't go far wrong with a simple shift dress. The figure-skimming, straight-cut design is a classic for a reason and now M&S has given it a pretty summer update. With its flattering, vertical stripes and pretty frill hem, it also taps into not one, but two of this season's trends. Denim Striped Frill Hem Mini Shift Dress Denim Striped Frill Hem Mini Shift Dress £28 at Marks & SpencerEasy to pull on, the dress features a square neckline and a neat zip fastening at the back. It's such a quick and simple way to look put-together in the heat.