one size fits all fursuit feet? is there a set in stone way to do it?

i checked memories but really didn't see anything so i hope im not digging up old questions.

i really do not like building off a shoe for feet, i was wondering about one size fits all or most feet where the wearer could shove in a shoe if they would like for extra support.

whats the best way of doing this so it fits most feet? i was thinking maybe working it out happy feet are made where its stuffed tightly on the inside. but i just want to make sure its pretty supported if that makes sense.

i thought i'd ask everyone here because this would be the place that would know!