there are lots of layouts available at that slagcoin site turnarcades mentioned...
http://slagcoin.com/joystick/layout.htmli looked through them and tried a few, and then i made some modifications and came up with the one i posted. it is similar to the standard Hori layout, but the bottom row is shifted to the right by 1/2 inch, which made it more comfortable in my opinion. i couldn't really use those templates, because they were in metric. yeah, i know metric makes way more sense, but in america, we don't use it. inches and feet have been imbedded into my brain for my whole life, so i just can't seem to make myself use the metric system.
plus, i wasnt sure i'd be able to get them to be positioned properly on the panel. so i figured i'd do it the old fashioned way, with a ruler, square and a compass. it didnt take that long and it worked out well.
i just knew that i wanted my buttons to be 1 1/2 inches apart, which is what they were on my first few panels of straight rows. i just raised the second column up half and inch, and the 3rd column up an additional quarter of an inch. the bottom row is the same as the top, but shifted half an inch to the right.