You should do both. Washing your face first gets rid of the excess dirt and oil, making the mask more effective. Washing your face afterwards gets rid of any residue...
It depends on ingredients you’re using, but usually, yes! For example, a mask made of cucumber and plain yogurt can last up to a week in the refrigerator.
Either! Both are totally acceptable. If you want to look more realistic, then paint your face. For a scary clown like Pennywise, a mask could be better, depending on the...
Once a week or so should be good. Don't do it too frequently. Oily skin can be treated with masks more frequently, about two to three times a week. Yogurt...
You can, but yogurt tends to separate when mixed with other ingredients. You should probably just make enough for one use at a time. If you have extra, let someone...