My favorite stamp sets are those where you get to create a scene using the stamps. Here I'm using the Garden Birdhouses. Having a variety of ink colors makes this easier.
If you don't have many colors of ink, try this technique, Stamping Off.
-Ink your stamp with a dark color
-Before cleaning the stamp, stamp again
-You'll have 2 images of different colors or hues
With very dark colors, you might be able to stamp 4-5 times, getting 4-5 different shades of that ink color. Like this:
I used a Blending Brush on all my cards to color the sky.