Masks are a great pick-me-up for your skin. You can do them about once a week, if you can fit it in or monthly. They definitely aren't an every day skin product, so once a week should be the max. They're a nice way to take a break, do something nice for yourself and just relax.
Masks are also great for targeting specific skin problems, as there is a mask for nearly every skin condition and ailment. There are masks that hydrate, reduce oil, firm, clean and shrink pores, assist with acne or just give skin a little extra boost. Always be sure to read the label instructions. Every mask is different in how it is used-some masks you only leave on for a short period of time and others you wait til the mask is dry. I've learned from personal experience to always read the instructions. I was using a mask that contained benzoyl peroxide and thought it was like any other mask where you leave it on until it's dry. I burnt my skin pretty bad. It was red and hot and puffy for the rest of the day. Turns out, that mask was only meant to be left on for 5 minutes-I had left it on for over 15!
Go give yourself an at-home facial and relax!