As much as videos show all manner of expensive time consuming load stacks for shot loads, an arch hole punch of correct size and three cheezit box card wads over powder and once or two over the shot works fine. Google old VM Starr on muzzleloading shotguns and read his amusing take and exploits.

His wads are described more as signboard/tablet backer (and good luck finding such today), but thinner fare works fine when a couple more added....when you find some downrange not burned through, you have arrived.

Ball loads even easier, a patched ball on powder. If burned through, who cares at the ranges being used. CAN put a card wad or three if desired, though...

It can be as simple or complicated as desired.