[owlglass]

Not research backed, but to add one data point, I bought into the whole "I need a three-step skincare routine" trend (which I think is positive, people should care for their skin as they should any other organ). However, after trying ~5 different cleansers (varying in ingredients, lathering vs non-lathering, and oil cleansing), I realized my acne is best when I cleanse twice daily with water.

On the other hand, moisturizing and sunscreen has helped with dryness and post-inflammatory hyperpigmentation from acne.

[spcebar]

I used to think I had oily skin, and so I would use harsh cleansers to cut through that oil. They didn't help at all, and I had bad skin for years. It took a skin conscious girlfriend to make me realize that I actually have dry skin, which produces an excessive amount of oil to compensate for the dryness. Just keeping my skin regularly moisturized and using a gentle soap or cleanser before bed/as needed cleared my skin.

[wazoox]

Just in case: for many people with acne problems, changing the pillowcase daily (or every other day, turning your pillow over the second night) seems to make a clear difference.