It’s 2014, shouldn’t we stop worrying about disk space? Nope, not at all! A modern MacBook might have a solid-state drive with just 64 GB of space. You’ll want as much space for your important data as you can get.
You can likely free up quite a bit of space by pruning away files and applications you don’t care about. Not everything here is obvious — did you know that each user account on a Mac has multiple Trash cans?