Using Gems for Level Improvement in Battle

For the Relief question, if you have a N2 caster. Then the most obvious answer would be to Forge a Thistle Mace. If you are looking for a explaination of gem usage and styles, I would have to say it's very situational. If I need something done as far as casting spells, I give usually 2 over the required casting, because of the tendancy to use gems for fatigue in the AI.

I also *never* apply gems that I plan on using in multiple battles. That means if I am having a caster cast Wrathful Skies and I want him to have them for a few battles, I only give him 2 Gems, and use a carrier to replentish him.