For a more intense workout I'd recommend a speed rope with pvc cord (and slim handles for comfort) in order to maximize spins. The one I use is a cheap speed rope ( ) I found at a sporting goods store for a couple of bucks. In my opinion cheaper ropes are as good if not better than the fancy ones with ball bearings and whatnot.
Rope length is crucial for a good workout because a proper length will allow for faster speeds and prevent the rope from dragging on the ground and catching your feet. A good way to determine length is to step on the middle of the rope with one foot then adjust the lenth of the rope such that the end of each handle touches your armpit.
Tips:
- Keep your elbows tucked in so that your wrists and not your arms are doing the work.
- Incorporate various footwork and tricks (sideswing, crossovers, double-unders, double-under crossovers, etc) not only to intensify the workout and improve hands-feet coordination, but to also lessen the monotony of the workout and make it fun.
- Jump on balls of your feet to lessen impact on knee joints so that your calves absorb the impact (great for toning calves)
- Use good cross-trainer shoes
- Don't jump on hard surfaces (I'm a bad example of this)
Buddy Lee has a great selection of training books and videos
Hope this helps!