One nice thing to look out for is a deck that will trash a gold or more to benefit each turn, then gain them back through means other than buying.
Apprentice / Hoard, for example, is something which can often easily be set up, where you use the gold to draw +6 cards, then buy a Province gaining a gold.
Apprentice / Haggler is along the same lines.
Best of all is Apprentice / Border / Village / Haggler.
Use Haggler to buy a Province, then Haggle a Border Village, gain an Apprentice. Use the Apprentice to trash Border Villages / Apprentices sufficient to do it all again.
As for Bishop, setting up a turn where you can trash masses of gold continuously is a lot of fun. I think I flagged a game of this sort in game reports about a month back (I'll try and find it) but essentially I lost heroically while trying to play a conventional Bishops -> Provinces game, while my opponent built a deck that drew his whole deck, played several Bishops a turn and gained a load of gold each turn.
edit:
Here we are:
http://forum.dominionstrategy.com/index.php?topic=1918.0and the linked game:
http://dominion.isotropic.org/gamelog/201203/05/game-20120305-112938-a21fcf0f.htmlA game that I lost against a higher ranked and more skillful player, and made me think seriously about Bishop VP as a full route to victory rather than as just a tiebreaker. Looking back at this game it didn't even involve Hoard or any clever gaining tricks, just lots of drawing and gold trashing