1. First gain the intuition
2. Second develop rigorous understanding
3. Third gain fluency from repetition
Repetition without understanding, or even intuition, is not really going to help.
There are game-based learning that really gets to the fluency part.
Of course this probably does not help with very tough questions that require out of the box thoughts, but I think it still helps.
I learned math by blindly following algorithms. Over time i gained intuition from seeing how variations in the input changed the output. The deeper understanding kind've slipped in there...I don't know how. I don't think you can build real understanding without rigorous practiced repetition.