If you need to type special characters often, the regular method might be a bit annoying, since you have to remember so many different key combinations. Free utility AX simplifies the process by letting you toggle through special characters with one key.
Even using the punctuation keys to type accents can get annoying, since each accent corresponds to a different key, and it's hard to remember which ones. With AX, all you need to do is type a letter and hit the accent button (F8 by default) to assign an accent to the letter. If the accent that shows up isn't the one you want, you can hit F8 again to cycle through the available accents until you find the one you like. If you have to type a lot of special characters, it's nice, because you only need to remember one key.
It also works with numbers (superscripting them), and certain other special characters (like changing $ to ¢ and / to ÷). It's a handy little app to have, and with the .cfg file located in it's installation folder, it's very configurable. Plus, it's written in AutoHotkey (so if you're an AHK expert you can mod it even further). AX is a free download and works on Windows systems only.