Before starting any project that requires you to hammer a nail it is absolutely imperative that you understand the proper technique. Without accurate knowledge about how to hammer a nail, injury is probable.
You can correctly hammer a nail by following three steps:
Position the nail where you want to drive it in. Be sure to hold it exactly perpendicularly to the surface you will be nailing. The nail should be positioned vertical and held in between your thumb and forefinger.
Keeping your eyes focused on the head of the nail, use your hammer to gently tap the nail into place. It is imperative you maintain eye contact with the spot on the nail that you are trying to hit. As long as you maintain eye contact the likelihood of missing the nail is extremely low.
Remove your fingers from the spot that you were holding the nail. In one or two powerful strokes drive the remaining portion of the nail into the surface you are puncturing. Remember to maintain eye contact the entire time you swing the hammer.
If you accidentally hammer the nail in crooked do not fret. Simply use the back of your hammer to straighten the nail and give it another sharp hit.