The ONLY THING is Practice.
i got 8% when i did precal 11 my first time because i didn't do any homeowork at all and attended maybe 5 classes the whole year.
took it again and actually went to class and practiced EVERYDAY i got 95% in precal 11 and now again over 95% in precal 12.
there's no magic tricks. only hard work and PRACTICE.
also, developing good study habits is essential, i suggest at LEAST 1 hour of math practice a day. That is what i did to get my marks
one last very important thing is to make sure you UNDERSTAND the material. if you don't understand, doesn't matter how much you practice or study, you won't learn a thing. I've made it my goal, not to get a high score, but to understand and learn as much as i can.
to sum it up
1) make sure you understand the material
2) practice
3)practice
4)more practice