I generally start with picking the stamped image I'm going to use. Then I plan in my head the general color scheme for the image.
Then I pick the cardstock that will coordinate with the colors I'm using on the image. I use quite a bit of pattern paper, so the colors in the pattern figure in there also.
After I get my image stamped and colored, I usually mat it with a die cut shape. I cut my cardstock layers, and then I can play around with how I will actually arrange the elements on my card, which embellishments, ribbon, etc I will use with it.
Bugga in OK
"Be kind whenever possible. It is always possible." Dalai Lama