Urgent Spell Questions

1. Call of Winds is a cheap way to get a flying commander to ferry gems around.

2. Put the reserve gems on a scout and have him sneak. That way you won't accidently lose your reserve gems in a fight.

Going hand in hand with this. Don't carry your "gem hauler" around in the same province as your primary armies unless you feel relatively safe with alot of commanders (I'd say 5-6 at the minimum, which you should regardless for anti-assassination/artillery spells). Use your hauler to resupply then either A.) If he's a scout; leave him there so he can take a artillery/assassination hit or B.) Get your Hawk or Harpy or something quick moving (sometimes properly equipped scouts, though you can make new ones at a lab for cheap) back to a lab for refill.

I do a similiar type of action with magic items I use for map movement (sea/air travel and such to jump over a lake or attack from an less protected flank). Fly in the appropriate items, move your troops then fly them out when they are not needed. Though this can be risky on scouts if they get assassinated.