Sizing balls are small beads of gold that are added inside the shank
but I stopped doing this many years ago.
Try instead adding a strip of metal the width of the shank,
approximately 1/2mm thick and a length that will be approximately 1/2
the circumference of the inside of the shank.
Next you will want to form it to match the curve of the inside of
Solder it only at the bottom with a very small spot of solder
allowing the ends to be lifted if necessary.
Harden the metal if needed.
This is more comfortable for the wearer and allows for some
You generally have to have the ring anywhere from 1/2 to 3/4 sizes
larger than the correct finger size to have either of these methods