I've been lifting for a while now, but have never developed any actual "thickness" to my arms.
I'm 5'7 with a small skeletal structure, and my arms measure 15.5" flexed, but they're just not "thick" like some lifters are (actually most lifters LOL).
Is there a certain technique to building thicker arms? Should I be doing heavier weight for fewer reps with a very slow tempo? Or do certain exercises and avoid others?