The LBD No 20-something should be without the all-important LBD. Opt for one like this classic Black Halo Olcay Asymmetrical Dress (£298) that's flirty without revealing too much. It's the kind you'll wear with tights and boots during Winter, wear to the office with a belted cardigan, and take out for your dressier events all year round. Image Source: dvf.com