It is a smart idea for people to learn how to pack their own shells, too.
Yes, it's a great idea for SOME people. It's not an activity for everyone. There are some people who definitely shouldn't try skydiving, either.
In recent years, the component costs have gone way up. Availability has been a problem too. There were weeks when I scoured the shelves looking for boxes of bullets and boxes of primers to restock. Powder was acquired in 8 lb containers and divvied out 1 lb at a time to "working stock". The 38SPL brass was usually good for about 8 reloads before the case mouth becomes "work hardened", then splits. The .357mag nickel plated brass is most likely to split. It's pretty, but I think the dissimilar metals limit the number of reloads.
A vibratory cleaner using ground corn cob and a tablespoon of Dillon brass polish does a fine job. If the brass is really badly caked with dirt, you can start with ground walnut shells as a more abrasive medium. Either way, you want the brass sparkling clean. Any contaminants on the surface may become embedded in the resizing die. That produces lots of ugly, scratched brass. Damaging a $20 to $30 resizing die is a waste of resources.
Always weigh your powder and stay within the suppliers recommendations for loading a cartridge. Bullet type, powder load, primer type, cartridge overall length (COL) should be worked from the minimum load first. Check the limits of your firearm so you don't exceed the manufacturers pressure limits in PSI or CUP (copper units of pressure).
“It is a smart idea for people to learn how to pack their own shells, too.”
Dillon Precision, the best reloading equipment available, and it is called reloading, not packing!