A few tips for invoker spells (yes yes, from a Battle god, I know its amusing)

First, do not focus on these spells all that much. Rank rank rank, is my first suggestion. You will use your combat spells in combat and they will shoot up. Then you return to spells like create spring/charge weapon when you have 5+ levels on that spell. This helps you with the amount of times you can cast it as you have a higher pool of mana to use and the cost is lower.

Second: location. There are indeed someplaces where it is bad to practice spells. A good rule of thumb is, if you know you are perfectly safe to sit there and not be attacked...then you probably wont get much improvement. Find a remote location either by exploration or by teleport.

Three: If you haven't increased in something after a while..wander around and do something else. Go back to ranking! Explore or whatever. Give it some time and then return a bit later and work on it some more. This will help break up the hours of spamming.

Four: If this is driving you nuts at the low level, then perhaps Invoker isn't the class for you. At least an invoker with such a low affinity. 4 and 5's will make it hell on you to learn some of the spells. If you want a faster time at the spells..go with 7 or higher.

That is just a few tips and chunks of advise.