Following is one of my somewhat common approaches to sharpening a TIFF file for print in three stages. The first time I sharpen is during noise reduction (I use Noise Ninja). Digital noise typically resides in the blue channel and removing it softens detail a little. I therefore first sharpen the blue channel.

Since color, tone, exposure, shadow and contrast issues were dealt with in Camera Raw prior to conversion, I move from noise reduction to layers, filters etc. - whatever is required to move the image closer to a final version. After merging layers I often make a duplicate layer, change to luminosity, apply smart sharpen with settings that can vary based on the image, then reduce opacity, often to as low as 10%.

Finally, after merging the sharpened layer, soft proofing and doing whatever else is needed I will often burn and dodge locally to enhance the critical areas of contrast and finish by locally sharpening those critical areas with a brush at very low settings (maybe 5 hardness and 5-10 strength).

I never sharpen very much at any given time. If I'm working on an image that will need a lot of contrast and sharpening work I'll sometimes duplicate the background layer twice, use the high pass filter on one layer then switch to overlay and reduce opacity to approx. 10. Then I will take the second duplicated layer, move it to the top, desaturate it and switch to hard light, again reducing to 10 or so. This is a common (for me) alternative sharpening method. There are many others of course like lab sharpening, plug ins (Intellisharpen is one I use - per Fred Miranda) and of course others.

Hope this makes sense. In no way do I consider myself an expert in this area - just a pilgrim on the path.