Windows: Typing special Unicode characters is usually a pain, but CatchChar can make the process completely seamless.
Once you've installed this simple app, keying in Alt-Shift-C will bring up a menu with quick access to commonly-used characters. Just click the one you want, and it will appear at your cursor's location. In the app's settings, you can also decide which characters appear in the menu, or edit the keyboard shortcut, though it must include Alt and Shift.
If you're not running Windows, you can copy characters from a webapp like No Tengo Enie, but CatchChar is as fast a solution as you'll find.