If you're as strict about your skin care as we are, you dutifully cleanse, tone, treat, and moisturize your skin every day and night. Not to mention the weekly masking and/or peeling. You do everything you can to keep your skin clear, even, smooth, and sparkling — but all that product might actually be doing more harm than good. Wait, what?We're talking about hygiene, people, and no, not the wash-your-bod and brush-your-teeth variety. Your products, just like you, need to follow certain hygienic practices to keep up that beautifying mojo.Some of them are kind of obvious, yet we all still do them. Some you might not even realize are causing issues. Product fouls can be as simple as opting for serums in clear glass jars or pumping your mascara — two choices that can lead to product breakdown or worse, bacteria growth. We don't have to tell you that beauty products are damn expensive, which is why it's in our best interests to take care of them.To educate us on the proper way to keep our products clean, effective, and bacteria-free, we tapped Mary Schook , certified aesthetician and product formulator; and Ni'Kita Wilson, certified cosmetic chemist and founder of Skinects . Ahead, they share the most common ways consumers are sabotaging their products. Read on to learn what's wrong and how to make it right.