As Stan says speed and simplicity is the key. Its very easy in the field to become distracted and misload your gun, especially with a SXS. Once I accidentally loaded both loads of powder in one barrel and the shot in the other. Fortunately, I tried to shoot the shot loaded barrel first. Now I inscribe a black ring near the butt end of my ram rod at the level it should be at when the barrel is properly loaded. KISS is the key!
Here is a photo of some extra tools I carry in my possibles bag.

The top is sample vials I use to hold powder and shot. You cant see it well in the photos but the vials are marked with shot size and gun theyre prepared for (I used to have both a 10 gauge and 36 gauge ML too). The screw cap for the powder vial is marked with black marker on the end.
The middle tool is a wad starter. One of my muzzle loaders is a 12 gauge Pedersoli that is choked IM and IC. The wad starter really helps get the wads past the choke. Its also useful if you have overly tight wads.
The bottom tool is for mounting percussion caps. Its a life saver on a cold day with numb fingers.
Like Stan does in the dove fields, for volume shooting I use a hardwood dowel as a ram rod. It works well and you dont even have to think about breaking it.
FWIW Treblig1958 that shot/powder dipper is really nice and I may just purchase one to help with preloads. Its easy to mark the preload so that you can quickly make a field choice.
Steve