Destroy!

Having watched 10s of Hollywood movies in the last 3 years, I have noticed something interesting. After using a set, it is customary to destroy it in the most gratuitous way, while filming it. This way you're making the most of your budget. In future, watch out for this, it's pretty frequent.

For instance, a bar brawl, a fire, a gun-laden mob hit on a building, or a building being knocked down.

It's a good money-saving tactic.