What little tip have you learned through trial and error that you didn't read somewhere or was told?

I recently discovered that to get rid of pillow face crease in the morning all you have to do is rub and pinch your face to increase your circulation and then wash in very warm water. This will help puff your face out and then wash with cold water. If the bags under your eyes are still puffy, hold a towel to your eyes and push firmly after the cold water rinse for about a minute.
What interesting home tip or beauty tip have you learned along the way that may seem strange but still works for you?