Winning a Clan War should give you gems
The title speaks for itself. It would create more incentive to actually participate and use teamwork strategy in the Clan Wars. I am not asking for anything unreasonable by Super Cell that would make them lose a profit. Reward the winning clan with anywhere from 5-20 gems per win. It takes a full 48 hours to go through preparation and war itself. That means if a team were to consistently be in war they would cycle through roughly 3 wars a week. A player could earn anywhere from 15-60 gems that week. That's not too much to ask for is it?