I love to make cards, so I do have tons of rubbers stamps and the line of supplies I carry, Arts Encaustic Int. BV, also has over 30 very pretty ones, which BTW are 20% off until May 31, 2011!)
Using a stamped image as a focal point can be very effective.
Here I used a solid stamp (all black). You want to stamp with a permanent ink, to avoid smearing, and let it sit a couple of minutes until it is all dried.
You can also use an outline stamp. Then you have to colour the image in before using your wax! You can colour with coloured pencils or ink. Take up some ink from your ink pad or coloured marker with a fine brush.
See image below.
Here is another free tutorial. This time to show you how to create a focal point with a solid stamp. You might want to watch it full screen to be better able to read the annotations.