Not to be confused with DNA origami, of course.

This picture is from an entry by Instructables user General Eggs in their ongoing Hot for Teacher Contest. Eggs shows you how to lay out the template manually using a pen and a ruler, before folding.

In point of fact, this is a common activity in biology education, and several free PDF templates are available for download, for instance these (B&W, color) from DNA Interactive. For teaching, the PDF templates are arguably better because they illustrate the chemical structures of the base pairs and the backbone in more-or-less their proper positions. Many sites credit Thoki Yen’s 1995 article in Trends in Biochemical Sciences for the idea.