Sky's the limit
From lurkmore wiki
The phrase sky's the limit, accompanied by a picture with a blank space, is used to encourage a photoshop thread. One of the most common templates for such pictures is Gendo Ikari.
Blank Check
Blank Check is a picture of a black and white male anime character, drawn by manga-ka Higuri You, but with the facial features photoshopped out. It was first posted with the message, "I've given you a blank check, go crazy." In that first thread, hundreds of edits were made of this picture, using memes such as Koffing, Cockmongler, V and Tom. The faceless character been given the name Doppelganger because of the fact that so much of the art is of past and present 4chan memes and can be considered a look into 4chan's glorious past.