In what order should I read this series?

This is a great question! The Villainess series can be read straight through. However, the story is enriched if you begin to read the By Blood or By Fire Series alongside it. While By Blood or By Fire can be read solo as well, my recommended order is:
1. Villainess
2. Taste of Ash
3. By Blood or By Fire
4. Villaness 3 (Title coming soon)
(More books in the series to be added to the list as they are released!)