They jump so have a good cover.
They come from soft water (GH below 100ppm) and pH below 7.0. If you want lots of male babies, raise the pH to about 7.6.
Have a thin layer of sand or gravel on the bottom of the tank. And lots of plants (Java Moss and Water Sprite are my favorites).
If you keep Nothobranchius species, have a margarine container with peat moss in. The fish breed in the peat. Most other killis (Epiplaty, Aphyosemium) breed in plants. Epiplaty species are the easiest to breed, followed by Aphyosemium and Nothobranchius are harder.
Feed them a variety of foods ranging from dry, frozen and live.
Keep the temperature around 24C because they age faster in warmer water.
Most species only live 2 years so breed them asap. They can breed at 2-3 months old.
Have an air operated sponge filter.