I have been playing around with a very effective border achieved in the following way:
Mark two parallel lines with a compass. Cut them with a swivel knife. Now use a lined sharp-tip beveler along one of the lines to make one row of indents and then turn the leather around to make the row of indents along the other cut line. The smooth and checkered bevelers, with the same shape, does not have the same good effect, but try them by all means, you might like their effect more.