It's very easy. I use the X-stream from BPI. 2 cents per each. They take up the same room as 1/8 oz of shot, so use a wad with more capacity than you normally would, and just push these in the shot before you close the crimp.
They do not need to be seated before the shot is dropped, contrary to some opinion. This way, you can use a progressive loader like a Grabber just fine. I've been doing it this way for years, and it makes a fine spread load. I do use a small screwdriver to push them in far enough that they don't interfere with the crimp.
