Is cleaning your face morning and night beneficial, or should it just be once a day?

I certainly wouldn't wash your face more than twice a day, and I wouldn't do it any less than once a day. On particularly hot, sweaty summer nights or if you’re using a lot of occlusive makeup, a second time is most beneficial. Generally, once a day is plenty for the less active face washers. This would not increase the probability of developing any more acne than if you did it twice a day.