Allow Attacks after a Clan War Has Ended
You know how you have always wanted to see how a different attack strategy or troop/spell composition may have performed against an opponent in a Clan War? My suggestion is to allow the attack page to remain open for a period of 6 hours after a war has ended so you can pick targets and try different strategies against superior targets you may not go after in the course of a clan war for fear of losing. This would allow you to improve your attack skills and learn how different troops respond in different scenarios. Obviously the war is over at this point and it would not affect anything with the war. This gives the opportunity to test yourself in war scenarios which you obviously don't get in multiplayer situations. Base layouts and clan castle compositions are typically completely different. You can even make it like a boost. For one gem you can attack a base in the war room after the war has ended.