I make the top piece of leather larger than the bottom one, get it wet in a warm water (put some glue on the edges and try not to get that wet), bond the upper and lower part just enough to keep in place during hand pressing the shape... at first I was a bit scared that leather wouldn't agree for that kind of action but after a hour of sweat and tooth crunching it turned just fine, looks to me like the top of the dr. martens boot... then I dried the top leather (took it of and dried the inside part also), glued it even better, cut the extra edges, sew it on an old pfaff machine, did the edges, lacquered it, polished and that is it...