I am sure there are smarter people who could figure it out easier for you but I'm old school and do it by hand. I tape together telephone book pages (you can use whatever paper you have) to the exact border size and trace out my pattern on them. Once I have it perfect, I then transfer the perfected design onto my border. If it's a simple outline, I just cut down one side of the line on the paper and trace out the edge onto the border.