My post-stacking workflow in DSS is:
1. Look at the histogram and figure out which colour channel has the most data on the left edge. Move the black point (left slider) for that colour to the right until it just starts to clip - you'll see this in the histogram with a vertical line on the left edge that starts to go higher and higher. Next, move the black points for each of the two remaining colours to the right until the main histogram peak is in the same location as the first colour's peak.
^ Note that your histogram will look a bit funny if you have a light pollution gradient, vignetting, etc.
2. Repeat Step #1 for the highlights if necessary. The stars are usually grossly overexposed with DSLRs, so I tend not to touch this. I usually leave the midpoint slider alone too (if the white balance was set reasonably well).
3. When you hit Apply, you should get a fairly colourless (black-and-white) image. Set Saturation to 20% and hit Apply. If your colour balance is out, it will look absolutely horrible. Carefully adjust the black point / highlight clipping sliders to remove any colour casts. You should have a reasonably colourful image at this point.
4. Use the Luminance tab to bring out the colours and details in the nebulosity. This usually gets me pretty close to my final result - I just do final tweaking in Photoshop.
Note that if you have a red background due to light pollution, it's best to remove it by clipping the red channel - don't try to remove it by adjusting the middle slider or you'll never be able to fix the colour balance.
I've attached an example of Sculptor Galaxy - raw stacking output on the left, stretched version on the right. Hope this helps!
