1) .45 Auto is the easiest cartridge to reload.
2) If possible, separate seating from crimping
3) Crimping is just to remove the case mouth flare/bell and NOT to crimp the case into the bullet
4) Stick with fast powders for accuracy
5) I prefer 185-200gn bullets to 230gn
6) Start with real jacketed. Buy from Montana Gold, Precision Delta, or Zero (Roze Distribution or Powder Valley). Don't waste your money on plated bullets. The above jacketed are superior and cost the same.
7) Before trying any lead bullets, slug your barrel and be sure your lead bullets are at least 0.001" larger than groove diameter.
Best accuracy is generally with AA2, Bullseye, or Red Dot.
9) 9x19 can be tricky to reload (case taper, very small case, very high pressure spikes if there is any bullet set-back into the case, barrels that range from a groove diameter of 0.355" to 0.362"). Don't be afraid to use 0.356-0.358" jacketed bullets depending on the groove diameter of the barrel.
10) measure the length of all sized cases and save the few that are within 0.005" of the max length. These will generally produce the best accuracy. Use the shorter ones for generally shooting and training.
11) case prep consists of at least wiping off the outside of the case and inspecting for crack in the case and at the case mouth. Anything beyond that is due to reloader's need to "do something."
12) Use data from reputable reloading manuals. Check several and start with the lowest starting load from the various manuals.
13) Buy Lyman #49, at a minimum. Speer, Hornady, or Sierra manuals if you want. Richard Lee's Modern Reloading has the most loads, being a compendium from many other reloading manuals.
14) Unique is probably the most "useful" powder for almost any handgun, but some people can't stand how "dirty" it is or they can't get it to measure well. It is very forgiving and the target shows no effect of a +/- 0.2gn charge variance. AA5 is also excellent in my guns and meters superbly.
15) Learn how to determine the COL that works best in your gun(s) and remember the COL in loading manuals is always a minimum that you should not go below without knocking off several 1/10ths of a grain.