I used to do these contour tans for body builders, for their competitions. I used to spray tan them around a 10% and then using an airbrush I would use a 16% for the contours of their muscels. It looked fab but I never saw them after showering, I just thought it must be good as they kept coming back for more!! They only every wanted it when competting and never had any complaints. I covered this when I trained with Su-Do many many years ago. But with practice you'll acheive it. I use my normal spray tan equipment (T200) and then have a airbrush to add the contour. If I do another one I post some pictures. (heres hoping!!!). HTH