1) Make hand motions on what you want them to do (most animals respond quite well)
2) Always reward your pet when they accomplish the trick. Otherwise, they will lose interest.
3) When rewarding them, that doesn't always mean treats!!! If you give them a treat only once, then just expect them to do it again without one, you are wrong. They love tummy rubs or just a pet, because that's a reward in itself to them.