If like me you are in the middle of editing a huge word document, in my case a book of 70,000 words, then you are jumping all over the place and it is driving you mad. Word does not seem particularly helpful here and you keep losing place of where you are. Especially if you are editing anything academic where you keep needing to go to the bibliography to enter references as you edit the text.
Well with a bit of luck I discovered that if you click the weird little circle (called 'Select Browse Object' in Microsoftese) on the scroll bars (between the double up/down arrows) you can set the double arrows to jump to headings you have declared. Simply by setting the chapter headings to be Heading 1, including the bibliography, you can now zip around the document very quickly to move things and edit, etc. I tried using the bookmark function but it so poorly implemented that it doesn't even compare to this browsing style..
Update: Even better tips include editing the preferences to turn off the fonts (so that they are not rendered which slows down the computer), and turn off the automatic word count, which also slows the computer to a crawl...