My advice
Only tumble one caliber at a time. Trust me on this one, 35 years reloading, and I've never made the same mistake twice. But I have made most of them once!
I always sort my brass before tumbling, and then again afterward. Before is by caliber, and after is by case and headstamp. Helps keep frustration down. It may seem like a lot of extra work, but spend a couple of hours getting 9mms out of .45 cases and you will understand exactly what I mean.
And here's a tip, don't waste your money on a "media separator". For less than 5 bucks you can get a plastic bucket and a colander (for draining pasta) at the grocery store. Put the colander in the top of the bucket (matching sizes when you buy them makes it easy), dump the tumbler in, shake/stir gently. Media winds up in the bucket, cases stay in the colander. No mess, no fuss, no bother.