Blending??

I'm still learning the ins/outs of digital processing and working with PSCS3. I see many posts mentioning blending two exposures to control dynamic range.

Questions?
Do you process each file seperately first, make your adjustments, then blend them together?
Or do you blend the two exposures first then make your processing adjustments?

Is it better to take two seperate exposures with the intent of blending, or can you just process the same RAW file once for highlights, then once for shadows, then blend?

Finally what is the process for blending in PSCS3, do you use the HDR-blend tool?

Thanks for any suggestions/advice!
Kevin

HDR is a way to blend exposures but is different from manually blending using layers.

Personally, I make few adjustments to the RAW files, bring them into CS, layer them, blend them then make any additional adjustments after the shots are blended. There are several ways to blend multiple exposures. You can use layer masks and the Brush Tool. You can use the Layer Blending sliders accessed by double clicking on any layer above the Background. These are the two I use most often. Making the majority of your adjustments and edits after the two (or more) shots are blended lets you better control how the the multiple exposures work together and enables you to better control colour consistency. If you make adjustments before blending, you may have to undo some of those afterward.

As far as double processing a single RAW file, while this can work it's not going to be the best option. You're not getting any additional brightness range doing it this way, you're merely shifting the existing brightness range to one end or the other. If you're going to double process a single RAW file, I'd argue that you can achieve the same result with careful editing of the single RAW file.

Double processing or even triple processing is an excellent way to make the most of a single RAW file. I rarely have to do it but sometimes a troublesome scene with deep shadows and bright highlights require me to process in Camera RAW for highlights, midtones and shadows. I open each up in Photoshop and save as psd or TIFFs. I blend them and then process them through my usual digital workflow. The blend is done using layer masks NOT HDR-blend which sucks in Photoshop.
You can also take two exposures and blend them but my preference is to get it all in one shot.

Here is a simple tutorial to get you started.
One of Ron Bigelow's dozens of outstanding free tutorials is titled 'Digital Graduated Neutral Density Filter'...you may find it helpful, too.
I try to get the individual exposures processed correctly before layering them.
Blending two (or more) images with different exposures will almost always result in a more pleasing finished final image than using a single RAW file. If you blow the highlights of a single exposure, there's no way to recover them, and if you reveal the shadows of a single exposure too strongly, then you'll likely introduce noise.
An obvious exception would be like many of the images produced by the previous poster, who incorporates breaking ocean waves in much of his work. In that case, no two images will be alike re: subject matter.

Note that using CS3, after I drag one image on top of the other while pressing the Shift key to snap them into alignment, I highlight both layers in the Layers palette and then use the new Edit->AutoAlign Layers function. If there is even the slightest degree of movement while capturing your image sequence in the field, this step will make any necessary corrections while automatically aligning the images perfectly.

Here are another three ways, the second of which takes 30 seconds once you've done it a couple of times.

Thanks for the suggestions everyone. I will have to try out some of the techniques mentioned and see what the results are.