Mostly the skills i forget to use are ones that have specific functions that i just don't need. For SCH its the skill that sends the fairy away. The only real use i can see for that is one that probably doesn't exist: using it after you're raised and your fairy is dead (you probably cant use it in that case--i assume your pet has to be summoned for it to even light up).

For AST, its the skill that ties you to a single-target, who then receives a portion of your overall heals. This is for tanks i guess and it just never lasts long enough for it to really be effective. Also sleeve draw and a few of the card discard skills. I only use the discard skill for the initial draw and not spread or rr.

For WHM its actually Cure 3. Mostly its Heal Buff skill + Medica 2 or 1 and i actually save it for those instances. I use the heck out of Asylum in dungeons especially during large trash pulls. Asylum + regen + medica 2 = thin air quickened holy spam with no need for healing. Pack dead. :3