List of profiling techniques, from the most desirable to the least desirable from the standpoint of accuracy:

1. Select a 128x128+ uniform feature-less patch in your working image and build a rough profile; then fine-tune the profile manually (analyze several more feature-less areas, the larger in size the better) or use auto fine-tuning;
   
   
2. Do (1) with another image from your camera/scanner shot/scanned in similar conditions; (optionally) additionally fine-tune it with your working image (equalizer values shouldn't change much when images are shot in similar conditions);
   
   
3. Do (1) with another image from another camera/scanner of the same model shot/scanned in similar conditions; (optionally) additionally fine-tune it with your working image (equalizer values shouldn't change much when images are shot in similar conditions);
   
   
4. Get a ready-made profile made with a similar image from another camera/scanner of the same model; (optionally) additionally fine-tune it with your working image (equalizer values shouldn't change much when images are shot in similar conditions);
   
   
5. Do (1) with a smaller (64x64+) patch from your working image;
   
   
6. Cut out a 63x63- uniform feature-less patch and (preferably) seamlessly clone it in an image editor to produce a 64x64+ area; do (1) with the resulting larger area.
   
   
7. Up-size your image (using your favorite method) in an image editor; do (1) with it; process the upsized image in NI (do not process original image with such a profile); down-size the result in the image editor.