I actually do most of my sharpening In LAB mode. Here's my basic workflow:
1. Convert RAW, doing as much CA correction, exposure and color adjustment as possible to minimize tweaking these later. Output to 16-bit ProPhoto.
2. Neat Image if necessary, custom noise profiling the image if possible.
3. Edge sharpening with Focus Magic, usually Radius 2 and amount 75-100%.
4. Convert to LAB mode and select the L channel only.
5. Do 5 iterations of USM sharpening on the L channel with the highlights and shadows masked off to prevent clipping, starting with a large radius and small amount, and working to a small radius and large amount. This allows extremely agressive sharpening without causing halo artifacts; you can sharpen as much as the image wants without having to worry about sharpening artifacts being a problem.
6. Shadow/Highlights on the L channel with no masking, tonal width and radius 15, amount 5-15% depending on the image.
7. Convert to RGB.
8. Any remaining miscellaneous stuff like cloning dust/acne, minor color tweaks, etc.
One handy way to get rid of CA is to run the dust/scratches filter on the A & B channels in LAB mode. Then select that as the history brush state, go back one step, and use the history brush to paint away the CA. This also gets rid of the type of purple fringing that is the same color on all sides of the object, which standard CA correction will not fix.