I have used a T/C NewEnglander 12 ga for several years now. I have tried many combinations for patterning, and the best I've found is a simple procedure.

I use card wads I cut from old milk cartons with a .740 diameter punch I had a kid at the local vocational school make for me in machine shop. I put 90 gr of ffg Goex in then follow with 2 card wads. Next is the shot which is 100 grains volume using the same adjustable measure. Follow that with another card wad and it's ready to cap & shoot.
Be sure all wads are fully seated!!!!!! They can trap air and move back up in the bore if you aren't careful. You can take a small punch or needle and make a hole in the center of the over-shot wad to let air out, but I don't bother - I just use caution in making sure the wad is fully seated.


edited to add:
Forgot to mention it, but I found "winchester-weatherby-mossberg" (the older models that fit all those brands before they changed sizes) choke tubes will fit my NE. They are about 1/16" shorter than T/C (they recess at the muzzle when screwed in), but work fine for me.
An advantage to the card wads is they can be inserted (sideways) through a tight choke.