As well as being an ASOS Stylist, Rachel Mae is an absolute treat on Instagram. Her feed is an absolute treasure trove of fashion inspiration and styling tips – a prime example being this pic of the lady herself in her Calvin Klein bra top. The 90s revisit, originally made cool by Kate Moss and Marky Mark, has been having a total moment through 2014 – Kendall and Poppy D have been showing us their Calvins all year, and, finally, it's summer so we can get ours out in full force, too. They're the ultimate in cool-girl base, paired easily with jeans for day and the so-now A-line miniskirt for night. Either way, you'll be onto a winner.