I forgot when I posted the question to post my own practice:
I'm about 50/50 on whether I take just a rifle, or a shotgun and rifle. Lately, I've been taking just a shotgun and letting my partner handle the rifle (usually my wife). Also working on getting some dogs with my bow, as well as trying to get some video dropping dogs with my Ruger Mark II pistol.
For the shotgun, I hold 6x 3.5", 7x 3", or 8 2.75" shells, plus 5 on the stock for 11-13 on the gun. I used to carry another 10-20rnds on a shotshell belt/bandolier, but now I have two 8rnd "slips" that slide down into AR mag pouches on my kit.
For rifle, I keep 20rnds in a 30rnd mag on the rifle, and another 20rnds in a 30rnd mag in my pouch. If I go through 40rnds of .223rem, either I was shooting like junk, or I have a lot of skinning to do.
I don't know that I've ever ran out of ammo unless I was just pitching long balls after a runner on a hope and a prayer.
I don't like taking time to restock at the truck (or rather I FORGET to restock), so I tend to just keep everything in my pack and carry it with me. I usually keep an extra full box of rifle and shotgun ammo in the truck all season, but I like to just keep my pack loaded with everything I need and only have to remember to take ONE THING, instead of loading a bunch of stuff, or forgetting something at home.