Coming from a guy that is in his thirties and still occasionally gets acne breakouts; while I also don’t think looking young and baby faced is the best most desirable thing, I do prefer to look younger rather than older.
Case in point: when I was 29 there was a job I was in orientation for with dozens of other people and on the second or third day we were split into separate tables/groups. The table I chose happened to have guys that were younger than me, but the funniest and most confidence boosting moment came when I got to know the stern older looking guy across from me (my initial guess for him was at least 35 years old).
Turns out he served in the army and spent a good deal of time outside, in the sun and so on. I thought he would appreciate good ol slapstick humor so when I threw out a joke, I referenced The Waterboy movie. He got the joke but looked a bit confused and asked me how old I was, noting the old movie, and his face of shock was priceless when he found out I was older than he was (he was 27) yet younger looking hahahaha. The others told me I could pass for someone in their teens.
Anywho, maybe in addition to acne, I think keeping hydrated and taking care to properly protect your skin from sunlight/burn is also a key “secret” ingredient. That being said, I would never go so far as to even consider things like Botox injections to appear younger.