Another option is to find a pair (or small group) of isolated empire-aligned systems on the edge of the bubble. The fewer inhabited systems in 15 Ly radius, the better. If these systems have few starports, and supercruise distances are short, even better.
In such a setup you will find lots of data or cargo missions going to the same destination. Just pick every mission from imperial factions that is donation, data courier or small cargo delivery, possibly passengers as well if you can fit a cabin. This does get boring after a while but it boosts your empire reputation nicely.
Just a note - many of these places only have outposts so it's better to have a small or medium ship when looking for them.