I'm not going to pretend that I know all their is to know about reloading or guns, but I have been loading for 10 years now, so here goes. Remember, you asked.... This crap applies to pistols, and revolvers, and works for me.
First step, figure out what bullet weight/design you're going to use.
For instance, if you have a savage .223, you're going to want to shoot mid to heavy weight bullets, if you have a remington .223, you're going to want to lighter bullets, the twist dictated bullet selection.
Then, grab a few load books, and do a little research about which loads seem to be popular, start there, don't bother re-inventing the wheel, that's what the books are for....
Locate a powder burning rate chart, and see where the popular powders are in rate. Now, if you're gonna shoot it in a shorter barrel, use a powder near the fast furning side of the chart, use reason, don't deviate from the common sense range of operation of the powder in question.
Get the components that you're going to use, and go over to your bench.
Grab a bullet, an fired case, and the powder in question.
I sort my brass and use brass from one maker, it's a hassle, but I think it helps.
Get a minimum charge weight of the powder you're using and charge the case with it.
Verify the weight of the powder charge on the scale you're using, check it twice.
Now, get a maximum charge weight of powder, and charge another case.
Does it all fit in the case?
Would it be a compressed load?
I seem to have the best results with powders that, in their desired range, that almost touch the base of the seated bullet. Kinda 'eyeball' the powder charge, and see if the bullet would touch the powder if you had seated it.
This will have to be part one, I gotta go to work now.
If you want part two, respond to this thread, and I'll continue....