I got into this one late so I cant add much. I agree with putting in range time and experimenting with different powders and bullets.
I started muzzleloader hunting two years ago out of necessity. I couldnt draw rifle tags to save my life.
I am somewhat anal so take the rest of this with a grain of salt.
I put around 500 rounds through my Traditions Vortek before settling on a bullet and a load. Along the way I found several that would be acceptable but I knew I could do better.
I finally ended up using BH209 powder with a home made 463 grain cast boolit in a Harvester crushed rib sabot.
Guess what- it paid off. Two muzzleloader mulies this year.
Just like the violinist who asked a guy on the street how to get to Carnegie Hall. His response- practice, practice practice. So true.