Carry a silk handkerchief.
Credit: Hugh Threlfall / Alamy

Few items are as versatile, or as effortlessly stylish, as an actual handkerchief. It's a subtle and simple touch, and it can be used for your schnoz, for dabbing away someone's tears, for mopping your brow, or for wiping up the sweat rings left on your desk by that afternoon scotch on the rocks.