Making a Text Highlighter
In MS Word, you can make text look as if it's been highlighted with a highlighter marker. It's a handy feature when you're trying to emphasize text in, let's say, an article. Can I do that same type of thing in InDesign?
Absolutely! Just press the Highlighter button! (Sory, just kidding.) The trick to making a highlighter effect in InDesign is the Custom Underline feature, which you can find by choosing Underline Options from the Control palette menu when the palette is in character formatting mode. Or, even faster, you can open this dialog box by Option/Alt-clicking on the Underline icon in the Control palette.
Unfortunately, when you select some text to apply this effect, InDesigh highlights it in black, which obscures the effect you're trying to achieve (while the text is selected, at least). So, when creating this effect, it's often a good idea to choose Window > Arrange > New Window -- this way you can work on the highlighted text but also see the effect in another window on your screen.
Anyway, once you have some text selected and the Custom Underline dialog box open, you can give the text a thick, yellow (or any color) underline. Then adjust the Offset to set the highlight in the position you want vertically.
Here's a sample of this highlighting effect (before and after):
Now here's the important part: After you make one of these, save it as a character style! (Just Option/Alt-click on the New Character Style button in the Character Styles palette, then give it a name and click OK.) As long as the character style is set to only apply this custom underline effect, you'll never have to go through the trouble of making one again -- just copy that character style from this document to wherever else you need it.