She did a recent tutorial on coloring with markers and colored pencils on colored cardstock. Asela's blog is Hop Art Studios... and if you haven't checked her out, run over there quick... and more specifically, Asela's tutorial can be found here.
This is a quick run-down of that tutorial, edited for white, smooth cardstock. I think this produces such a vibrant result. I know the popular way to use Prismacolor pencils has been with Gamsol (AKA odorless mineral spirits). This is my preferred method...
Step 1: Stamp an outline image. I've used Palette Hybrid in Noir with an Outlines Rubber Stamp. Isn't this an amazing flower outline? I really love it. I have all three sizes of the flower.
Step 2: Using markers, color the image carefully with a light ink. I used Pretty in Pink SU marker for the petals and So Saffron for the center.
Step 3: Highlight the colored image with matching Prismacolor pencils (I had to practice a bit to see what would match first). I used Rose to color over the image. I colored in darker on the folds to add dimension.
Step 5: With a blending stump, meld the colors for a smooth and seamless result. I keep a piece of sandpaper handy to "clean" the stump between colors or when it gets excessively dirty.
Step 6: Finish the card. I colored multiples of the flowers in different sizes to layer for added effect.
I'll have another quick tutorial tomorrow or Sunday to show another way to highlight an image.
Edited to add: The colors in the final card just weren't done justice from my camera.