A little image I drew up for myself to make into a 'no soliciting' sign.
Original version and a blank can be found here: http://arcticwanderer.tumblr.com/post/128570973948/made-myself-a-thing-for-the-door-took-about-two
(don't know how to make short links here, sorry...)

As stated in the link, you can use it for making your own signs. :)