Well, rooting hormone usually helps a lot.
But let's back up a little bit here. The best time to take a cutting is in February when the tree is as close to dormancy as possible, and will be waking up again as the day lengthens and the weather warms up.
Make a cutting from a healthy whip branch (long single and skinny)
Between 1 and 2 ft long. Use a SHARP cutting tool. Denude the cutting of all leaves and put in the shade and out of danger of frost. Leave it there until tomorrow.
The the next day, soak the cut end for about an hour and then roll the cut end of the whip in rooting hormone. Then place the whole in a 1 gallon black pot using a good composted soil mixture. dr earth trees and shrubs is good for this. Water and keep moist but not wet from now until the end of summer.
Also, you might want to do this with 5-10 cuttings. Cuttings of nearly all trees have a low success rate, and this will at least help you have 1 success. You can keep or give away any others if they survive a whole year in the pot. At that point it's safe to plant them into the ground in the fall or early spring.