Take a long hard look at the sky

Take a: picture
long: ¼sec exposure
hard: hand-held
look at the sky: box

Yes, it's cheesy.
Yes, I apologise.

Ok, so ¼sec isn't exactly a long exposure, but I did also take a number of ½sec and 1sec exposures too, but I found they let in a little too much detail. And the hard bit was that it's virtually impossible to do a decent long exposure photograph without a tripod, unless you have extremely steady hands.