I've been using a soft plastic brush to clear out the big stuff then
using my household vacuum to clear out the fine particles. Anyone have
a different technique?

First, buy a fresh new filter. Then pick up some "fine filter bags" to
install inside your shop vac. You will rarely, if ever, need to clean the
filter, and the bags make it much easier to dump the debris when the vac is
full.

Before I started using the filter bags, my shop vac filter would clog up
frequently with sawdust and other fine dust. I would take it outside and
beat off as much as I could, but it just clogged up again the next time I
used it (putting additional strain on the vac motor).

Anthony