There are a lot of ways to paste text. The most common way I do it is with the Command-C and Command-V shortcuts. However, a lot of times you are working with text that is carrying a lot of formatting baggage and when you use the standard paste, the text shows up in your document unusable. Most apps that deal in text give you an option to paste and match formatting and the keyboard shortcut for that is usually Shift-Option-Command-V or some near-variation of that. The trouble is that the shortcut isn't universal and, even worse, some apps that involve text fields don't have any support for an option to paste as plain text.
TextExpander to the rescue. This is perhaps the easiest snippet I've ever posted. I just invoke the clipboard formatted as plaint text. My snippet is xpt (X-Plain-Text). This works everywhere on the Mac. (Even Microsoft Word.) I find typing x-p-t much faster than wrapping my fingers around more complicated combinations or mousing into menus.
I've also got one for pasting rich text from the clipboard, x-r-t, that I use much less frequently.
I know this is a bit obvious but I showed this to a friend recently and she thought it was pretty swell. You can download my clipboard snippets below. Also, I've got a lot more snippets for download over here.