My personal solution over the years has been a special certain pocket to put loose caps in. I have in-line cappers and a ted cash snail capper.
Rifles arent too much of an issue. Pistols are tedious to cap without spilling caps. Muskets had big caps that made it a lot simpler.
I have extra cylinders for my 58's. I prefer my Colts (dont ask why) and the snail capper works on them. The debate goes on as to whether they really swapped cylinders back then. I would say they definitely did not on Colts but a man once showed me an actual account of an officer saying he did swap cylinders on his Remington.
The Polish capper costs $185 and ships from Poland.
I see guys making "star" cappers on 3-D printers. They are a 6 point star made of plastic and each point is notched to hold a cap. They would work fine on a '58 and if it was black in color (not blaze orange) then it would not be much of an eyesore in the shooting pouch.
I have punched holes in leather to hold caps but have had them fall out and get lost if material shrinked.
Our Missouri Partisans were devastating when well mounted with two or four revolvers against infantry with single shot muskets. Reloading came later.
I once saw an original 1858 Remington with the barrel cut down to 4 inches and the loading lever removed. The story goes that the original owner was a stage coach guard. He claimed he wasnt concerned with reloading because, after 6 fast shots, you were either dead or the fight was over.
Attached pic of David Poole.