We could cut out $400 per month fairly easily by eliminating eating out, a $100 storage unit (yes, I know, and it's going soon), and a little bit of miscellaneous.
Beyond that, though, I don't think there's much we could cut without also cutting income dramatically (I could cut out my commute by quitting my job) or compromising health and safety (on the level of not fixing brakes/not eating a balanced diet, etc)
We'll likely choose to cut the storage and keep the eating out and miscellaneous, and work a little longer at jobs we love to pay for the two we keep.
Beyond that, well, I could and should cut down on our cellular bill a little bit. It runs $70 a month for the two of us, and I think I can get that down to $30-$50. We could cut out home Internet, but then I would have to go to work more frequently instead of working from home sometimes, and it would just add to the fuel costs. I think we would lose money that way.
Basically, we stripped down the bare bones in order to be able to build our house, and we've never ramped back up. I don't think we either of us see any need to do so; we're happy with things the way they are. Except for the storage unit, of course.
Edit, having looked at my expenditures: "Miscellaneous" is bigger than I thought. Make that $600. Most of the extra has to do with finishing the house/maintaining the (long, steep, unpaved) road into the house, and related new-home expenses that I think will dwindle on their own as we settle in. Though we may have to pave that damn road to pull it off, and that won't be cheap.