Here are the tips I give every new inline ML shooter.
1. Forget about the pellets. Yes, they are more convenient. However, that convenience comes at a sacrifice to accuracy.
2. Many guns will not shoot Powerbelts accurately. I won't even try them anymore. Good Hornady SSTs in sabots shoot better, hit just as hard, and cost less (the T/C Shockwave is a Hornady SST with a different color tip and a higher pricetag).
3. Remove the breech plug and wet swab after EVERY shot. That prevents any crud ring buildup and ensures that your sight-in will mirror an actual hunting shot.
4. Learn to be ABSOLUTELY consistent with your powder charge volume and ramrod pressure. With a ML, consistency translates to accuracy.
5. Get some of those pre-load containers to take hunting. I use the kind that store a pre-measured powder charge, bullet, and primer all together. A piece of masking tape holds everthing together.
6. Speaking of masking tap, put a small roll in your backpack. If it starts to rain, use a piece to cover the muzzle and another piece to cover the frame gap. This will help keep stuff dry. The tape is soft enough that the shot blast will blow it right off.