This tip couldn't be more simple: A check box in InDesign opens up a bunch of options – and most people don't know it's there.
When you go to place a file, at the bottom of the dialog box is an option to "Show Import Options."
Selecting the check box will open an additional dialog box giving you options that change based on what kind of file you place.
Place a PDF, Illustrator file or InDesign file and you have the option to choose which pages or page range you want to place. You can even turn on and off layers.
Place a Word file and you can map style sheets in Word to their equilvalent in InDesign. Although my favorite option here is to "Remove Styles and Formatting from Text and Tables" which basically converts a Word file to a text file.
And other options are available for other file types. It's a little hidden feature, but it can make your life much, much easier.