I find the concept of farming for the express purpose that you can farm some more to be a ludicrous proposition
I try to make the boring stuff as mindless as possible so I can get back to doing the fun stuff faster. A little pain now goes a long way (Farming Dios so I could max skill a Myr being the best example I have)
With Star Den only open for an hour that means (for me) trying to get in as many runs as possible during a given timeslot. A Button team maximizes the runs per hour I can fit in. This yields me more +'s so I can hyper teams sooner. Farming SDR's is pretty much the only boring thing I farm that still requires a little bit of thought (matching around locked orbs).
Hell getting Mathena off the ground and farming arena took a fair amount of effort and that's paid off handsomely.
At this point in the game for me there's four things I can be doing at any one time:
Farm (skill ups, evo mats, stones via challenge mode)
Challenge Dungeons (current set completed day one)
Arena(s). Arena is a little stamina heavy for me most of the time (unless I find a Mathena Partner to consistently run with. Finding DC folks is a pain.)
Team Build: I have a ton of fun finding workarounds for a dungeon's mechanics to make up for my less than reco skill level. Then there's just teams together for variety's sake.
Farming is the least fun thing to do and with the skill revamp coming I won't be doing it nearly as much. +'s are still super important for Arena and new dungeons so I'll continue
farming STTD as often as I'm able.