Pitching wedge, sand wedge, and lob wedge should be used 90% of the time. I don't recommend doing a whole lot with the eight and nine with exception of 40 foot and above running chip shots or greens with a lot of contour at that distance. Why?
Because you must learn that trajectory, not spin, is what makes you a great short game player. hitting the same trajectory shot all the time by mixing clubs does not teach the FLW all it wants to know.