I've started to experiment creating pano images using the PSCS6 Automate>Photomerge feature. I'm starting out using 3 RAW images and would like to hear what workflow you've found most efficient, most successful.
Do I merge the 3 RAW images in Photoshop, save (in what format?) then bring the pano image into ACR? Or should I first process the 3 images in ACR, save, then merge in Photoshop?
I can tell what I do ("discovered" thru trial and error): I would do individual changes/corrections in ACR and then go into PS to merge them. HOWEVER, remember if you make changes to the individual shots that are not uniform, they may show these differences after the panorama merge. Therefore, have the corrections of one apply to all!
After the merge make sure to zoom into different parts of the merged photo to correct any remaining problems-- especially where the individuals were stitched (you may find vertical lines which are the "seams" that is easily corrected with the clone tool or the spot healing tools, e.g,).
I just realized I did not answer all of your question, i.e. saving the file(s). If you can, always save the originals and which type of file depends on your choice, e.g. JPEG is a smaller file size (but is a lossy file) while PSD or TIFF are larger but lossless.
Others may have different suggestions
After your merge, in your layers panel, you can save the shots you used to create the panorama using something like TIFF or PSD and then flatten the image, if you so desire, using keyboard cmds, e.g. Shift + ctrl + E or go into Layer>flatten .
Just as you must keep the same camera settings from image to image when shooting the panorama sequence in the field, you must also process the images with the same parametric edits image to image. My workflow involves shooting in raw, processing the images in Adobe ACR (Photoshop) and then opening them in Photoshop. I then stitch the images to generate the panorama and save it as a PSD. When I initially access the raw images in ACR I open all of them at the same time. Then I click on the Select All button and make my adjustments.