Have you ever gone to bed without washing your face? Or neglected to use moisturizer because you didn't think it was necessary? While skin sins range from fairly innocuous to downright dangerous, we've all committed at least one at some point. Join us over the next week or so as we—the bloggers at Mario Badescu Skin Care—confess our very worst skin sins.

Let me begin. Forgive me, dear readers, but I’ve come to this blog today to confess a rather serious skin sin: I spent years (most of my teens and twenties) not exfoliating my skin.In the world of skin care, this sin ranks somewhere between never moisturizing and—the very worst of them all—tanning. While nothing can beat tanning in the canon of serious skin sins, neglecting to exfoliate left me with dull, congested, miserable skin. I think that exfoliating is one of the most underrated things you can do for your skin.

To start, let’s talk about this strictly in terms of acne treatment. When there is excessive oil in the follicles (the pores) of your skin, the oil begins to act as a glue, trapping the dead skin cells on the surface of the skin. Bacteria becomes ensnared inside the pores, resulting in acne. You need to exfoliate away those dead skin cells to achieve clear skin.

And aging? Well, the skin begins to shed dead skin cells more slowly as you age, which can make your skin look dull and, frankly, older.

Furthermore, exfoliation makes it possible for treatment products to penetrate the skin. Think about it: would you try to apply stain or paint to an old, rough piece of wood? You’d probably sand it first, right? (Equating skin exfoliation with sanding wood may be a mistake—remember to be gentle with your skin!)

These days, I use a cleanser with Glycolic Acid two to three times a week. The Glycolic Acid is a chemical that literally eats away at dead skin cells. You can also use a scrub to exfoliate—but only if you’re not currently experiencing acne eruptions. Now that I’ve confessed, it’s your turn. What your worst skin sin?