Take cuttings from the tips of the healthiest and most vigorous stems on your jade plant. Use cuttings at least 4 inches long and remove any leaves from the bottom 2 inches. The larger the stem you use, the faster your new jade plant will grow into a sizable specimen.
Dip the cut end of your jade plant stem into hormone rooting powder. Place it on a bright windowsill until the cut surface dries out and forms a brown callus. This can take up to two weeks.
Plant the stem deep enough in compost to support itself. Plant small stem cuttings at least an inch deep. Use a compost made up of 3 parts sieved, peat-based compost, 1 part 1/8-inch horticultural grit, 1 part coarse sand and 1 part perlite; or a mix formulated for succulents.
Water as soon as you have planted the stem cutting, providing enough to moisten the soil throughout. Place it on a west- or south-facing windowsill that receives bright, indirect sunshine. Cuttings will root best at temperatures of between 75 and 80 degrees F. Keep the soil barely moist until new growth appears.
Place growing jade plants in the warmest and brightest available location in the home. They thrive with at least four hours of direct sunshine every day. Fertilize with a liquid feed formulated for succulents every three months.