To grow a successful cactus you must let the fresh cutting callus over and heal. Place them in a dry, warm place for up to 2 weeks. The larger the cut surface is, the longer it needs to dry. This may sound extreme but remember cactus are drought tolerant. If you choose to use a rooting hormone make sure it is powder! Do not let your cactus cuttings get moist or wet.
It is easiest for your cactus cuttings to root during warm weather. According to the University of Arizona, the best time to propagate your cacti is during August & September when the soil temperatures are warm and conducive to rooting. Some shade is best for rooting and will prevent your cactus cuttings from sunburn.
Pick a good container with drainage holes for your callused cactus cutting. When planting your cactus use a well drained soil mixture designed specifically for cacti. Plant the cutting about 2 inches deep and pack the soil around the cactus. I also use small rocks to help keep the cuttings from falling over. Wait about 2 weeks to water; then soak the cactus well and let it dry out another 2 weeks. The biggest problem for growing cactus is over-watering. Too much water causes the roots to rot. Cactus are dormant during winter. Do not water a cactus during cold weather unless it looks shriveled.