I must agree with Marie on this-- If you aren't happy with what those pencils are doing already, there's no suggestions or tips to make it better. Student grade pencils simply aren't going to do what you want them to.
Have you considered either Blick's colored pencils
or the Soho pencils
Both are artist grade, available as open stock, and really inexpensive compared to the other brands. I haven't tried them yet, but from what I've read and seen from the folks who *have* tried them, they're a great value.
Another thing to consider is looking on ebay for used pencil sets. Folks can find great deals that way-- just remember to investigate the seller.
Another way to go is watch hobby stores like Michaels or Hobby Lobby. Both sell prismas, and can have outrageous sales sometimes.
Long story short, if you want to work in cp, it's worth the money to get a better set of pencils.
Hope to see you sharing some of your work (regardless of what pencils you're using!) soon.