It's not a fun task picking them up, especially when I would rather be doing some clay. There is also the chance of getting spiked by one or two when trying to clean up.
I chanced upon this tool at the local Wilko's (a fabulous shop selling all kinds of home related thingies).
For around £1.65 It was definitely worth a try to see if it helped to pick up those pins.
Taa Daa. This should stop me stepping on a pin I missed later on. It couldn't pick up the larger Fimo piercing pins (about 1.6mm) as they were too heavy for the magnet. Those larger pins are so much easier to see when you have dropped them than the thinner (around 0.7mm) pins.