Women are loyal to their make up like they're loyal to their men. Once you find "The One," there is little reason to look elsewhere. What a lot of women seem to to overlook, however, is that there is a huge difference between being loyal to your favorite volumizing mascara, and being loyal to the very first volumizing mascara you bought over a year ago. Holding on to makeup for indefinite periods of time is one of the most unhygienic things you can do. Flawless make up application only begins with the purchase of amazing product; it ends with the proper care of your makeup library.
SPF- All SPF products have expiration dates. Go to your bathroom and check your favorite tinted moisturizer, setting powder, or lip balm. If the expiration date has passed, you are no longer being protected from the sun and its harsh rays. Holding on to a product after its SPF expiration date may also compromise the fundamental quality of the product, as the essential compound of the make up was formulated around its SPF ingredient.
Brushes- Make up brushes that are used for powder application should be washed once a week, while brushes that are used for liquid application should be washed daily. You can use your everyday products such as face wash/shampoo to wash the brushes, or you can invest in cosmetic brush cleaners ($5-$20). Massage the cleanser into the brush in the direction of the hair. Be sure to pat the brush back into shape before it begins to dry. Waiting long periods of time to clean your brushes will cause oil/bacteria build up, which can lead to break outs.
Mascara- Mascara should never be kept for more than 3 months. There are obvious reasons for this: because the lengthening, thickening, and volumizing effects won't be as effective; but also because the bacteria that can build around the applicator and inside the vial can cause eye infections, irritations, and even sties. And don't ever share your eye applicators with friends - that is one of the fastest ways to spread germs.
Bags- In my experience, the best make up bags are the ones that have enough room to hold my everyday essentials, but not enough room for me to stash every product I own (trust me, there are a lot!). I love this bag by Space NK because of the space it allows for brushes and lip products. Piling all of your product into an unorganized bag will just make a mess and cross-contaminate your make up.
As women, we should always want to look our best and present our best face. Take measures to properly care for your make up product and accessories, so that you never look less than Made. :)