Exactly what I did with my set ups. I went with 72 hole racks (8 x 9 hole pattern) with the 9-holes on the horizontal. The left edge is labeled 1/8 and 1/16 on the appropriate rows. Makes it easier to find the 1/2" collet by running across the 1/8" row.Just for fun, you could add some visual aids, to make it easier to find a given size collet - either outline the even eighths sizes with a silver Sharpie, or add labels. I've found this to be nice timesaver for drill indexes, etc.
I can't quite picture thatExactly what I did with my set ups. I went with 72 hole racks (8 x 9 hole pattern) with the 8-holes on the horizontal. The left edge is labeled 1/8 and 1/16 on the appropriate rows. Makes it easier to find the 1/2" collet by running across the 1/8" row.
Bruce