What one thing is good for every skin type?

Obviously, sun protection.  But that's not my topic today.  The one thing that I'm talking about is SLEEP.  I've read this numerous times, and I've done my own informal research.  Like many women, I wasn't fortunate enough to leave acne behind when I got into my twenties.  It obviously loves me so much it can't be without me.  It did seem to improve some during my twenties, but by the time I got into my thirties it was back, worse than ever.  I went on a mission to find the best concealer and foundation, which at the time, was Laura Mercier (and arguably still is).  I started going to the same dermatologist as one of my perfect-skinned colleagues.  For some reason that we didn't question, we got microdermabrasion, glycolic peels, and facials for a $30.00 co-pay.  My colleagues' skin stayed perfect, and mine stayed littered with giant red bumps (known as cystic acne).  Nothing seemed to help very much.  Until I lost my job.  Which also meant that I started sleeping more.  Now I only occasionally get a large zit.  You might say it's because I don't have job stress, but anyone who's ever been unemployed for long and has bills to pay knows how much stress that causes.  So the only answer I'm left with is the sleep.
Try it!  It can't hurt anything, but it certainly can make you look better, and also it makes you feel much, much better.