And for real trash, experiment with detuning (or not tuning at all) the drums. Try it with totally undamped two headed kick drums and single head toms... Maybe buy some crappy used drums and beat the tar out of'em!
The worst that can happen is that they sound too "good" by mistake, right?
Another method I've read is some guys use crummy built-in tape recorder mics or other "toy level" recording gear to get that super junky lo-fi thing going. Might be worth an extra track.
