Element philosophies.

[blinks]

Get things to the point where you can look at a card's effect and know its element without knowing anything else.

I tried to take as many dimensions as I could and split them between elements so they all felt significantly different right off the bat.

[blinks]

I believe the fallback spells can all be neutral, and I think you only need two at this point:

• drop a tendril in your location (one mana)
• move yourself home from astral (two adjacent diagonal mana)

I think everything else can be drafted, or a spell on your home card.

[blinks]

• Fire / Air is a quick-moving mage that shoots fireballs, but they're a glass cannon that has to re-target with each attack.
• Air / Water is a flexible, hard-to-predict mage that can send out a bunch of chaff to hide their intentions, but they're poor at reacting quickly.
• Water / Earth is a slow-moving "tower mage" that might only cast one actual spell a turn, but affects the whole map with their permanent-power, wave-like tendrils.
• Earth / Fire is a tank with a flamethrower, prepared to deal with nearby threats but unable to affect the distant map.