Also: what's a good way to get better at Skill Shots?

(for instance, I like to jungle Cho'Gath just because of how much delicious sustain he gets in the jungle, but for me, Ganking with his rupture is, well, huge, and just as important a source of damage with him. Unfortunately, my lack of skill with skill shots is showing. Do I basically just practice until I get competent with skill shots in general or more along the lines of a champion to champion basis?