Use ARA and avoid test boosters until your at least 30 years old. Eat, train, lots of Protein, clean eating in general, creatine is cheap and effective. Don't be in a hurry like everyone else in the gym to get big or get cut or get anywhere fast. Take your time, less is better. Doing more than your ready for will lead to injuries and problems that will impede your progress down the road. Don't drink and don't smoke dope or cigarettes. It will hold you back big time. These are the years you want to build a good foundation and where your testosterone is highest.