I guess it depends on where your feet are getting sore, but for me it was the boots being to big. My arches started cramping. I rode an entire season cause I figured this must just be unavoidable, although all the rentals for years hadn't caused cramping, but I figured must be cause I am riding more this year. I tried footbeds, strectching, loosening lace, repositioning bindings and forward lean, nothing helped. It all went away when i bought smaller boots.
I still get pains and soresness, but nothing so bad that i need to stop riding. I think there's pain from general riding/new boots and then there's pain from having the completely wrong fit. just need to figure out how to tell the difference.