I'm not at all a carpenter, I'm not good with wood and I don't have the power tools neither so, this will be a test of what I can attempt to make without the help of a professional ! Since I've never tried-on pattens before and I really don't know what's confortable and practical over what's not, I'm gonna give a try at two models ; A flat one made out of one piece like image B above and a higher one with two heels made out of two peices and articulated as well like fig. A.
I find fig C's staps practical and convenient so, I'm gonna give a shot at this model because I fear that the "nail attachment type" would rip too easily.