Half of the time, that first cut is sufficient to release the nutmeats intact. When second or third cuts are needed, you will soon learn where they are to be made for each type of shell piece. Most of your cuts will be to the outer portion of the shell from the blunt end of the nut. Don't waste any time at the pointed end of the nut. Small nuts are very easy to work with as the nutmeats practically fall out when one end of the chamber is exposed.
Larger nuts require quite a bit more work because of the odd lobe shapes.
Because of my arthritic hands, I can crack only about 50 large nuts per day, but I can do 100 of the small ones, as they are so easy. As the nutmeats are released, toss them into a container which is at least two feet away from you so that little bits of shell and shell powder clinging to your hand are either too light weight or too heavy weight to follow the same path, and both end up in the discard bin immediately below. No one likes to find bits of walnut shell in food. I like to vibrate the nutmeats on a screen to be sure to eliminate small debris prior to storage. Nutmeats that are to be used in the next few months can be stored in plastic bags or mason jars.