My sister got bunch of pimples upon forehead and cheeks when she got home last week. She's really in the problem and she kept asking me for a help. I will share to you again my few routine in avoidance of pimples :)
• Make sure your hands are clean when you are going to touch your face. I am really Obsessive Compulsive about my hands every time I do a lot of tasks, I usually clean my hands after it and I really feel like I am DIRTY when I forgot to bring alcohol and face towel through outdoors. Wash your hands perfectly especially your nails. Sing at least 1 song up to the chorus or a happy birthday 5 times. I often cut my nails and I believe it is one of the causes of pimples.
Image source: http://www.bodley.ox.ac.uk/dept/preservation/training/handling/cleanhands.htm