Well this is how I do it. Everyone has there own method, so this is kinda like a "cliff notes version."

The basic tools. Drill with socket adapter to hold brass while spinning in front of torch. For those new at this I suggest you use some temp tape so you don't over heat the brass and make it too soft.
I then have a turkey aluminum liner from Wally filled with water to drop the hot brass into.
After cooling I let the brass dry completely.




I then prime the case, now I use a standard primer in most cases, but in some I use a magnum. In the case of making the 3" 410 shells I'm using a very robust brass case that's made to contain very high pressure, so it's a magnum primed case and it does have a little more powder than usual. It's the last bit of some cases closest to the rim that is hardest to fill out properly.But for most fire forming I load in about 8 grains of unique, fill the rest of the case up with cream of wheat, but be sure to leave about a 3/8th of an inch at the top for the wad and the glue seal that's needed at the top. As you can see in this image , I opted to use a bit of foam to keep the powder and the cream of wheat separate. I used it because it was easier to set straight and flat against the powder.





I've used cork, cardboard, pasteboard, tissue paper for wads but the best for me was a stiff pasteboard.


For shooting I just load from the data books. Primer, powder, a cardboard wad over powder than a few cardboard wads or cork to cushion the shot. Pop in the over shot wad and seal with water glass and let dry overnight. By playing around with powders and wads you should have an acceptable load recipe
that should give success in the field. If you don't mind shooting the 2-1/2" length shotshell, than use the off the shelf 444 Marlin brass. It's a basic prime, powder, wad, shot, wad, seal and shoot. Now go and have fun.