Then found this: http://www.rufflesandstuff.com/2009/09/silhouette-pictures.html
So simple! You can print things on your normal printer, on normal paper and then just cut round them.
Here's one I made totally inspired by Ruffles and Stuffs:
Hubby's birthday card:
So my attempts are amateur. I should really lie and say that the kids did these! But I had fun and it's quite addictive. Simple cutting and sticking makes me feel indulged. I was surprised that you could get small details by just using scissors rather than using craft knifes. I will be doing more!