Just a quick tip this evening, which I may have mentioned before (I can’t find the post if I have). Its a very simple and quick way to complete words using any Cocoa apps such as TextEdit and Mail to name a few. Although I don’t find it that useful for completing words, it is great to help you find spellings to long and complicated words that you may not know.
To autocomplete any word start typing and then press Option + Escape or just F5. You will then be presented with a long list of words where you can use the up and down arrows to select the word you want.
Very simple and very useful. I might use it more and more.