Sometimes I just want to pick up my needles and start, without swatching, without calculating, without even a completely clear idea of what I might end up with. This approach has it's risks, of course, but I'm willing to take them on.
So I started a wool hat at the top and worked my way down. When I finished it was just a little too big, and just a little too loosely knit. So naturally I felted it.
Also naturally, it is now just a little too small for my big ol' head. The good thing about hats, though, is that you can almost always find a head to fit one.