That method is okay but, what if apart from that you had to do something "special". Like killing an special creature, complete an special quest...
And not an specific one, there could be different things to choose.
As always, apologize me for any mistakes made, cause English is not my native language.
I mean, you have to improve your abilities, but appart from that, you need an achieve.
For example, you gain 10 points in Destruction, okay, you are ready to advance in level, but you need one more thing.