Once you get the Shadowcraft Elfstone, put it on Idrial. From there, get Crippling, followed by Fear. Maxing it out is not necessary but is fun. From there, go to Eregion and to that small little gully-like area that has a high build up rate for battles. Just wait for the battles, then kill all but one enemy. Have Idrial fear it, then just max out all the desired skills. Keep the enemy feared every time his face gets close to the top of the roster on the upper right-hand screen. You can even have everyone else retreat but her then just max out her skills using Drain Inspiration, and eventually Leech Inspiration, from her Swordcraft set. You can even maximize item crafting and Lightcraft Elfstones if desired. After she is maxed out, move the Shadowcraft Stone to another character. Get fear on that one and continue the same strategy.