Generally the board should come to your chin for a smaller board (park rider) or to the top of your head (free ride mountain)…Many board companies offer a "wide" model if you have big feet. A wider board generally has a slower edge to edge response. A shorter board generally doesn't hold a edge as well on groomers or float as well on powder. To me stiffness is also a big factor. I would suggest you demo a board or two before buying.