This is to finish answering a very important question posed by WavyVirus that went unaswered and I felt didn't fit/belong in my most recent thread about skills/spells and their development.
You may have covered this, but is there some scarce mana-like resource which would force the player to choose carefully which spells they cast and when?
Yes, I covered it partially but didn't state in detail how it related to limiting which spells they cast and when. The resource is called Will. Its' regeneration is affected by a few things. One of them is the health condition which I mentioned earilier in this post, Thirst. When you're character has been in combat for a while (even if he hasn't used magic much or at all) it affects their thirst which directly affects their will regeneration. This can be countered by drinking water mid fight or using certain Water Weaving techniques which drain some of your will but add additional will recovery.
The way I proposed to limit/promote effective spell use is simple. Will regen will be ALOT lower during combat. Outside of combat it will regenerate at a decent pace which is still pretty low but will promote training while still posing a challenge.
Aside from will recovering during resting (fast forwarding time) I wanted to implement a mechanic which is the equivalent to meditating. This would play out as a sort of minigame which focuses on timing and concentrating. It would be centered around things which would imitate focusing the mind. The main mechanics in the minigame would be things like landing a shifting bar on a marker, pressing a button at the end of a circle reaching an inner ring. Basically things that require timing and reflex. Doing so correctly would allow you to regenerate your will at a vastly improved rate per successful portion of the minigame. During the minigame your will regen will be higher as well. This will promote training/passive combat by allowing the person to start meditating and afk for a minute or two if they dont particularly enjoy or cant be bothered by the minigame.
Hope that helped further my point/clarify things