Although to level restoration using healing spells, you must make sure that you are actually gaining health from the spell and not already at maximum health.
Destruction wont level unless you actually hit something with it.
The other skills can be trained up with repeated ON SELF casting.
Nifty way to level destruction is to conjure things then shoot them with fireballs.
Destruction also works with on-self casting, just like the other spells. For example you can make low cost weakness to fire spell on self and cast it to self train.
Although to level restoration using healing spells, you must make sure that you are actually gaining health from the spell and not already at maximum health.
Actually even casting restore health on self at maximum health DOES traun Restoration, as the spell still has a valid target.