What works well for me is, as soon as I get them, I put a dab of wild Halloween fingernail polish on each needle. One dab for one size with the identical number written down on a piece of paper that I tape on the package, with the right size, two dabs with number written down. I can see right away what size it is, even without being able to find my magnifying glass. Of course I have to use something to see the numbers in the first place, but then the glass can stay lost for a while.
The dabs of fingernail polish goes under the gripper so it does not affect the sewing.