Apart from the handclaps and snaps (which I did by, y'know, clapping and snapping), all the percussion loops on this track were created with a guitar. The high pattern is the B and E strings, muted at the tenth fret. The low thud is an open palm lightly hitting the bridge pickup; then the track is doubled and one version is fed through a low-res filter. The bass guitar (my Hofner in drop-D tuning) also doubles that rhythm, which adds to the thunkiness.
If we ever do get this one into the studio, I'd love to add some true drums, probably with some Adam Ant–style heavy tom beats. But one thing at a time.