I just use the rectangular marquee tall, if I want a border that runs along the bottom and top I make a selection in the middle leaving gaps at the top and bottom then hit Ctrl+Shift+I and fill it in.
if you select the pencil tool, any color, about 1-5 pixels, the just hold shift to make the straight line across top/bottom, and sides
i just used the marquee tool and do one at the top and bottom and fill with black, its fast and easy,