One way to save time, particularly if you find yourself needing to cross-reference documents is to view multiple documents concurrently. Unfortunately, this can be unwieldy if you only use one screen. Luckily, dual monitor users have another powerful option at their disposal. They can use the 'Acrobat Monitors' option to tile two or more documents across the full width of their desktops.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.