My moms get moved between a high intensity and a low intensity light environment based on how fast I need them to grow. When I don't need them to grow any bigger I keep them under a mix of LEDs and CFLs, and when I am going to need long branches for cuttings I move them under a big metal halide bulb for a while.

Don't be too scared to trim them down to size either - just don't take too much off at once and shock the plant. Cannabis is a hearty plant and they can usually recover from a pretty savage trimming as long as you leave them with enough fan leaves. Also, bending and tying branches down can keep a plant low and wide.