Boots

Safety boots do a pretty good job of protecting your feet against all kinds of mishap, such as stepping into nails and dropping things on your foot. When working on structural stuff they're not at all optional.

They don't make you superman, a steel toed boot is not going to allow you to kick through concrete walls, but you'd be amazed how much difference it makes when you get something heavy on your foot the first time and it doesn't hurt at all.

Even if these shoes/boots protect you, there is no protecting you from stupidity, and no amount of armour plating is going to protect you when you drop a 2000 pound weight on your foot (in fact you'd probably be better off without steel toes in that case).

Good boots cost a fair amount of money, but then again how much does a new foot cost ?