Join Date: Nov 2013
Location: Lake Gaston, NC
Try doing one is a piece of scrap wood the same species as you want to build the table from. Hog out most of the material in the mortise with a drill, and clean it up with a chisel. Cut the mortise first, and fit the tenon to it. There are all sorts of ways to do it, but doing a few by hand will give you an idea of what's required, and some good experience.
If I have one, or a few to do, I'll do the mortises by hand, and sometimes the tenon too. Look on my "Windows" page, and you will see a project where I had to do hundreds. After cleaning the mortise up, even if cut with a machine. I fit each tenon, mostly with a Paring chisel, and wood files and plane floats once it gets close.
Some machines can fit them perfectly to start with, but I'd encourage anyone just starting to learn by hand first rather than spending a bunch of money on something when you will probably decide later that you'd rather do it a different way.