Chris, There are a few different kinds of hip quivers. Do you have a pic of the type you are referring to. When I want to make a quiver, knife sheath, etc, I first make a cardboard(poster board) pattern and adjust it by removing material or adding material until it works out the way I want.
Give us a better idea of what you are looking to make and someone has probably made one and can give more details about how it was made and the dimensions.
Pat