You should apply a face mask after bathing, but not before that. The product needs to be absorbed into your skin and have time to dry out before you try it on. If you put the mask on right after taking a shower, it will remain wet for too long and suck up all of the moisture from your skin so that when you take it off there is no longer any benefit from its use. You can also apply a facial sheet or clay afterwards if desired.
How often should I use my facial sheet? Is once enough?