Not all stamps need to be carved though. I recently started playing with an alternative idea. It is east to cut or burn into craft foam to make a stamp, but you can't make more detailed stamp.
I added a narrow metal tip to a bottle of Puffy Paint and drew a free form plant design.
You can see where my first start looked bad, so I wiped it off leaving a black smear.
After it dries, which seems to take forever, just brush on paint and stamp!
This doesn't create a deeply etched stamp. Though when you play around with it, there are cool things to do with it. I used it for stamp but also for collagraph type printing. Sorry no photo, but if you paint the whole surface, lightly stamp on scrap paper, then press hard on desired surface. Use a brayer or rolling pin. Very fun effect.
Here is a little collage I used this stamp in:
I started with a flash card
Glue on tissue
A little paint and paper
Now stamp! I used both white and black paint