Done!
Oh. You meant aha.
Similar to Mangetout’s point: never let yourself fall prey to lazy thinking. If you spot another track for that train of thought to travel on, stoke up the engine and steam on.
I second the point about learning new words. IME, the more precise your potential word choice, the more precise your thinking, and increasing the range of objects and ideas you can name increases the range of subjects you can think about. Oh, it will also make you seem smarter, of course.
Oh, and turn the TV off unless you are sure your life would really be worse without that particular show on. I’m a big fan of selective viewing, but ‘wallpaper television’ makes your faculties flacid.
Another point about looking smart…
Spelling and grammar - don’t make silly spelling errors, they look dumb.
If you’re unsure of which punctuation to use, I recommend “…” and " - ". They make you seem like an intellectual racing among chains of lightning thought who can’t be bothered to waste time deciding what kind of pause you wish to suggest to the reader. 
I just read my own post, and I seem to be suffering from Alliteration Overload. Still, it does make the post sound smarter …