Avion, I went back to have another look at the belt picture you posted...I'd say you're stitching skills are there! Do plenty of practice on paper first with the layout, so you can get the proportions you want. I lay out 2 lines the width of the belt, then factor in the border stitching and creasing first, then play around with proportions till I get what I like. Once I'm there, I use the paper layout to help with putting the design on the leather. I take the measurements from the paper with the dividers and transfering to the leather, although I suppose you could do it the same way you would for tooling/carving with a tracing (something I'm not too good at).