There is a spreadsheet of 16 gauge loads on 24HrCampfire website that originated from the Yahoo 16 gauge users group.
Bulky powders and Guilandi SG-16 wad are your friend in Cheddite or Federal hulls, if you want to avoid fillers.
If you are like me, and cannot always get the ideal wad or powder, or just want to use what you have - cut 5/8 diameter styrofoam wads from meat trays to put in the shot cup, under the shot.