Set the Default Sort Order based on how these are grouped ...

Example:
ring sizes would be the 10 to 90 group
clothing would be the 100 to 199 group
etc.

Now you can sort within the groups by setting the defaults in increments of 5 or 10 to allow you to insert more later in the right order ...

Note: the Catalog ... Option Value Sorter can help a lot with this ...