i do soil so i dunno if ill help but heres my .02 cents.

Makes sure you get root hormone first of all. Pick a nice stem you wana make a clone cut it at a 45 degree angle and dip into some water [as to much sure air doesnt get up into the stem]. Then dip it into your root hormone and plant into [in my case] soil. Get some kinda of incubator type dome as keeko said, i've found that those salad containers from fast food places actually work good. I fill the bottom black part up with soil [after poking a few holes in the bottom] then i cut to small sections on each side of the top clear plastic peice [for air flow], then i put the clear piece on and spray my leaves to keep it nice and wet inside the homemade dome. So far i've gotten a 100% success rate with this even after transplanting, if you want pictures im sure i can make a write up, which i think maybe i will just for shits and giggles