Hopefully you got it figured out, but if not I believe the part you are looking for is as follows:
Quote (xxtmanxx @ Dec 21 2009 01:45pm)
Minimum Essence Required for Proficiency Points (tested at lower levels and hypothesized at higher)
Proficiency - Tier/Magic Level
level 0 - tier 1 magical+
level 1 - tier 1 rare+
level 2 - tier 1 angelic+
level 3 - tier 1 arcane+
level 4 - tier 1 godly+
level 5 - tier 2 magical+
level 6 - tier 2 rare+
level 7 - tier 2 angelic+
level 8 - tier 2 arcane+
level 9 - tier 2 godly+
level 10 - tier 3 magical+
Having no muting proficiencies, you need to start by muting tier 1 items that are magical in order to have the best chance at getting the essence. As you rank up, you can do higher tier/magic level items to get higher essences.