Combine Macro Filters to Get Closer
You can combine close-up lenses by threading them together. Adding a +1 lens to a +2 lens, for instance, yields the impressive +3 magnification that you see here. For that reason, I suggest getting close-up lenses as a set instead of one at a time; you can then combine them as you see fit to obtain the magnification you need for a given picture. When combining close-up lenses, put the highest magnification on first, closest to the camera lens. That way, you can remove the lenses in smaller increments to achieve just the right magnification.