If you are relatively new to Reporting Services, it can be difficult to keep track of all the report elements. Your report quickly gets cluttered with elements that are contained within each other.

Not a lot of people seem to be aware that there is an option called 'Document outline', that makes it easy to keep track of all the elements. Of course you will have to give all the elements a meaningful name 🙂

It also makes it easy to select an item within another item that both have the same size.