We shouldn't have to tell you twice that keeping makeup around for longer than you should is never a good idea – but then again, we all need a friendly reminder now and then. Taking extra care to use hygienic makeup practices is a habit that's worth its weight in gold (and clear, beautiful skin).
First of all, be sure that you're not keeping products for longer than you should. Always check expiration dates on makeup where applicable, and be diligent about throwing out your products once they're a couple months old.
If you use makeup brushes, it's especially important to keep these clean, as the fine hairs can trap bacteria and spread them around on your skin (we know). Wash brushes at least once a week using a gentle shampoo and dry them thoroughly.
For those of you who are still a bit acne-prone, you may or may not be sleeping with the enemy. It's a good idea to change your pillowcases often, as these are also some rather unsuspecting culprits when it comes to the harboring of pore-clogging bacteria.