To level up skills more quickly have Elegost in your party and use the "Arrows of Sleep" skill to immobilize the enemy, Then cast Berethor's leadership skill "Fellowship Grace" to regenerate any AP points used, then build skills with each of the other party members using skills that are nonevasive to the enemy making sure not to awaken them. Kill any enemies that are immune to the sleep spell.

Note: This works more effectively if you have Elegost's passive skills "Sleep Volley" which will affect all enemy's that are not immune to sleep spells, and Elegost's passive skill "Lingering Sleep" which will extend the effect of the sleep spell for the remainder of the battle.