Maxed Storages - Share with your buds
This idea embodies the entire concept of the clan. There is a second option if you don't like the first.
I frequently max out my storages (which are fully upgraded).
It would be really cool if any loot that is captured above the max storage level could be equally divided among all of your clan mates.
Second option: Any time you max out a gold or elixer storage you can upgrade a single wall piece for the normal cost. This would drop you back down and allow you to raid without wasting captured loot. Not sure what dark elixer could be used for unless you wanted to make it possible to spend like 10,000 dark for a wall piece. Or maybe create an inferno tower regeneration fund.