Step 2: Grind fruit
Weigh out your freeze-dried fruit, then grind it in your spice grinder. (Or grind a bunch, then weigh out 5g.) If you're going low-tech, a mortar and pestle would work too.
If you want to be super-careful, use a sifter to remove any remaining chunks when you're done. I didn't bother, and thought everything tasted great.