First, make sure you choose the right hammer for the job. Just like you wouldn't use a big sledge hammer to hang a picture don't use a small lightweight hammer to drive heavy nails.
Inspect your hammer before you use it, check to be sure the head isn't loose, that the handle is in tact and that the face isn't worn or damaged.
Always wear safety glasses when using a hammer. Pieces of nails, shards of wood and other materials can fly off when you strike the hammer and land right in your eye.
Next, the grip. It may seem like holding the hammer up near the head will give you more control, but it really won't.
When you hold a hammer, think about a handshake. The base of the hammer is the hand and the rest of the hammer is the arm. Grab the base of the hammer in a firm hand shake and you're set to go.
When you swing a hammer use your arm, not your wrist. This will give the hammer the force it needs to drive the nail straight and steady.
Follow these tips and you'll be safer working on your home projects! i'm Mrs. Fixit and it's just that simple!