I want to get that last bit around the edges of some pressed blushes and bronzers I have. So what's the best way to get that finely ground? If it's not fine enough, your brush picks up chunks of it that then fall all over the place. The only thing I can think of is taking the end of a brush or something similar and mashing it all.

I put it inside a plastic bag, then scrape the rest of the powder out with my finger or a Q tip (w/o puncturing the bag). Then i just crush the powder up w/ whatever I have handy (books work well).

I put mine in an empty mixing jar (like the ones I have from Everyday Minerals) and use the back end of my big powder blush from the body shop because it's flat.
:)