We should be able to send troops in, at no cost, to do a test or practice attack on a fellow clan members base. We would first choose a target clan member. Then we would make our troops at no cost and no waiting time. And attack like any other attack. No loot or trophies are gained or lost. All traps set off are automatically reset at no cost.

This would allow us to set up our base with more assurance that it will work and without losing cash or trophies. If we can see our base get attacked by a few people with different strategies, it will be better to prepare ourselves from attacks by other people.

On the other hand, if you aren't very good at attacking, you can find a strategy that works well on your clan members. A lot of times people in the same clan tend to have similar layouts because they look at each others, but will keep it a little more interesting when you go to battle for real.

Would find it interesting too to see how different clans would have more specific, kind of micro-cultural strategies and base set ups.