If you have really stubborn acne that won't go away then I'd advise to go to a dermatologist and they'll prescribe you with a medication like Accutane. It has an 80/90% success rate although it does come with a few minor side effects.
If you're just looking for a good skincare routine, then I'd advise you to use a cleanser/exfoliator followed by a Vitamin C serum, toner and then moisturiser.Don't over exfoliate though because you don't want to strip the natural oils from your skin completely. 2-3 times a week is ideal.
For me though, I've found that lots of water and a balanced diet works better than any creams/serums ever did. It's amazing how much diet plays into ones complexion
