Weightlifting.

Obviously, weightlifting is key when sculpting your body to the way you would like it to look.  It has taken a LOT of long hard days for me to get to where I am, and as you all know, I'm not even close to my goals yet.  Whether you are bulking or cutting, I suggest heavy weightlifting.  I know many people live by the thought "Light weight, High reps" when cutting, but it's not something I believe in.  Why? Because it never helped ME get my arms any more define, AND I lost muscle mass.  Since I've started cutting this time around, I've kept the lifting heavy - ish.  I usually do 4 sets. 12 reps for a warmup, then a 12-10-8 working set, increasing the weight every time.  The same routine whether I am doing lat pulldowns, dumbbell bench press, bicep curls, etc.  Obviously with the whole hi-rep thing, you will burn more calories, but you are not exerting your muscles to full usage.  I make sure that on that last rep on my 8 set, that its all I can do, I'm squeezing, pushing, and breathing at maximum capacity. When you're exerting yourself like that, you are burning calories and helping to maintain your muscle mass.