I used to get questions about making stamps out of eraser. I had taken those photos long time ago, but I forgot to publish it. Sorry ’bout that.
First of all, we need to have a carving blade set. I bought that set about 10 USD, I am sure you can find better tools if you live in Europe, USA or Japan (the Mecca of stationery stores)
I see foreign bloggers are using big blocks of rubber erasers and cut them into pieces as they need. Unfortunately, I couldn’t find them in Turkey so those are the biggest erasers I can find. The important trick there, if you are using erasers, it should not be too soft, otherwise it will break into pieces as you try to carve.
And the rest is after drawing the shape on the eraser, is doing like Rodin, just carve the excess and throw them out. So that’s it briefly. By the way, it is important to be calm and be careful not to slice your hand.