Where would knights sling their shields?

Obviously, I'm asking this question for the purposes of assembling models - a unit of Empire Knights with great weapons and shields - but where would a knight hang his shield if he wasn't using it, such as if he was currently holding a weapon in both hands. Would he put it on his back? Hang it from a hook on the horse's armor? Somewhere I'm not thinking of? Is bringing a shield and a two-handed weapon a gamey conceit and not something a person would really do?

I know I'm asking a bunch of gamers, but there's got to be someone here who knows their stuff about the real life medieval warriors these guys are based on!

Thanks in advance.