DARK CIRCLES UNDER YOUR EYES
The Cause: Not getting enough sleep. The circles are actually blood vessels that can be seen through more translucent, sleep-deprived skin.
The Fix: If sleeping in isn't an option, you don't necessarily have to reach for the cucumber slices. Anything cold contracts the blood vessels and makes them less visible; place a chilled wet washcloth over the area for five minutes. Finish the job with a swipe of a soothing eye cream, such as Zirh Restore Herbal Under Eye Cream ($28, bloomingdales.com).
The Upkeep: Preempt the circles by sleeping with the eye cream already on—and if you really want your beauty rest, prop your head up with a couple of pillows; this reduces undereye swelling.

WRINKLES
The Cause: Aging. In your mid-twenties, the production of skin-plumping collagen slows down, causing creases to appear.
The Fix: If you're looking for a little boost, use a serum with vitamin C to rebuild collagen and an antioxidant cream, like Lab Series Max LS Age-Less Face Cream ($65, labseries.com), to repair damaged skin cells. But if you need more dramatic intervention, see a dermatologist. The big-gun muscle relaxer Botox now has a competitor called Dysport. Both subtly iron out fine lines around the eyes or on the forehead. For deeper grooves under the nose or bordering the mouth, consider fillers, which add volume to weathered skin. Expect to pay $600 to $1,000 for either treatment.
The Upkeep: Use a serum with retinol or citric acid, like Fresh Elixir Ancien Face Treatment Oil ($250, fresh.com), to keep collagen production at its max. Re-up on Botox or Dysport every six months.

RAZOR BURN
The Cause: Rushing your shave. Failing to adequately lubricate your beard or pressing the razor too hard against your cheek results in red, chafed skin.
The Fix: Slow down. Before you pick up the razor, prep your beard. Begin with a hot shower; the steam opens your pores, which makes whiskers easier to lop off. Then apply pre-shave oil (a dime-size drop is enough), and when you do start to shave, use deliberate, measured strokes.
The Upkeep: Always finish with a calming aftershave balm, not a stinging splash. For a blemish-free shave, you have to replace your razors every five to seven sessions. Keep blades sharper longer by storing them in a shallow dish filled with a capful of pre-shave oil.

READ MORE:
Essential Grooming Tips for the Groomsman
How to Get the Barely There Beard
What You Need to Know About Your Skin