Water enters at the root, travels through the stem to the leaves where it evaporates out through stomata. The amount of leaf area cannot be so great the leaf desicates. Reducing in will help. Leaving pitchers on the cuttings and keeping them full of water may also help, the cuttings absorbing water through the pitchers. Once you have taken a cutting there are a few ways to root is.
Cuttings often root in live sphagnum, or rock wool.
I often take a cutting, place it in a small pot of sphagnum, place it in the relative shade and humidity of the floor of the greenhouse and treat it as all the other plants in regards to watering. Success with cuttings depends on the age of the material. The lower you go on a stem, the less likely you are to get it to root. Hormones can be used. Bottom heat can be used in cool weather, here I usually wait until mid spring for lowland plants and fall or early spring for highland species.