Process the ingredients in the food processor for a few minutes if you are planning on using it in chocolate, beverages, or icing.
For baking and candy making, you can just mix the ingredients together by hand.
Granular vs Powder: I've only been blending it when needed right before using it in recipes. I put a huge mason jar on my kitchen scale and just pour in the weight amounts of xylitol and erythritol and measure in the stevia. Then I shake it really well.Stevia Extract: You can use any pure stevia extract. Stevia should be the only ingredient.