Quoting April L Chapman:" OP Thanks for asking how to make one I have been wondering the same thing. And Mandy thanks for posting this link the other links I have tried looked way too complicated and this one looks super easy."
no problem! and also, i dont round the corners. i have made dozens in differnt prints, and they all turn out great with the squar corners. i cant remember if is said it, but i dont use trim either, i make this even more basic, lol. but yes, very simple and easy to make! good luck!