There should be something like a clan bank where troops can be donated so fellow clan mates can go and take out the troops they need. It seems like every time I get on to donate promised troops to a clan mate, we don't have the opportunity to be online at the same time. If there were a clan bank option, a player could go on, and take out the troops they need. And if the troops aren't there in the bank at the moment, request that a specific troop be placed in the bank, and check on it periodically. That would also fix the problem of people sending out troop requests in the clan chat asking for a specific troop, or troops at a specific level, but only getting donations that end up not helping at all. Example: A crystal league village getting lvl 1 giant or barbarian donations from a bronze league village when he requested anything level 4 and up. Those donations are pretty much useless at the crystal level.
The clan bank could also be used to introduce resource donations between clan members. There would definitely have to be a cap on how much each member was able to take out though. I'm thinking it would be good to set the rules of resource withdrawals to these:
1. You're only allowed to make one withdrawal a day.
2. The maximum amount a member is able to withdraw will be equal to the average ratio of however much is in the bank at the start of the day to the number of members in the clan. The equation would look like this: X / M = RPM
X: The total amount of a particular resource at the start of each day
M: The number of members in the clan.
RPM (Resources Per Member): The amount of a specific resource an individual member can take out each day.