I’ve always liked to use small blocks of wood to store router bits. I took it a step further and cut some cubes from 1 1⁄2"-thick stock. All you need to do is arrange the cubes in a drawer or on a shelf. You can use double-sided tape on the bottoms to keep them from sliding around.
All you need to do is drill two holes of different diameters (1⁄2" and 1⁄4") in each cube. Then mix and match the cubes to orgazine the router bits in your collection.