Step 1: An explanation of what I'm doing.
This works best with nails that are about 2 inches or longer. Any shorter and you might hit your hands or it just becomes cumbersome to work with them.
It is important to practice finesse and not strength. Nails are not as tough as you might think, and just a little bit of convincing will get them straighted up.
Step 2: What you will need.
1. A hammer
2. Bent nails
3. Soft wood (pine works great)
Optional gear... (we're being gentle and not smashing stuff, so there should be almost no risk of nails flying around and hitting you in the eye. Nor should we be overly worried about the hammer hitting you hard enough to crush or break bones/fingers. But it's better to be safe than sorry... so
5. Gloves (not heavy duty worker gloves, leather garden gloves are good)