Make sure you have a pair. Condition the fish on a high protein diet (live foods are best) for a couple of weeks. Do plenty of water changes. Always provide a place of refuge for the female in case the male gets too rough with her. Read up on the fish you plan to breed. There are all different types of spawners (substrate, cave, moutbrooders, etc.). Provide what is necessary (spawning medium, temperature, etc.). Fish will do the rest.