Other than some beginner's luck on my first try a few years ago, I've had kind of a black thumb when it comes to rooting cuttings. My best recent success has been rooting them in the ground, but I first bury a vertical piece of 1-inch PVC pipe so an inch is sticking up above the surface. Then I pour about an inch of perlite into the pipe, slip in the cutting so the tip is just sticking out of the ground, and then pour more perlite around it. Then I carefully pull out the PVC, adding more perlite as it settles, so the cutting isn't actually touching the soil (I started doing that because the ones I put directly into the soil tended to rot). I cover the cutting tip with a clear plastic container (with several ventilation holes) to create a bit more humidity, and drape a white rag over it to keep it from overheating. A drip emitter several inches from the cutting keeps the soil moist, but the perlite buffer prevents the bark from getting (or at least, staying) wet. Even if leaves emerge before the roots, I don't remove them--the humidity and light shade seem to be enough to keep the leaves from drying out, and that way they can photosynthesize and create nourishment that ( I think) helps drive root production.