Right now, the patrons have no flavor to me; they're just a choice of a spell list. Someone had suggested giving each patron things unique to that particular patron, an associated class skill, a pool of abilities like the oracle gets with their mystery, etc.
I think the hexes written by Dale McCoy are a wonderful start to that. Maybe there could be something about the bargain the witch makes with the patron. These are not (usually) divine beings; patrons are powerful parties who are helping the witch out for their own reasons, and they have their own agendas and plans that they are trying to further.