Editing HDR images
If you click on Edit HDR you have the possibility to add your own highlights or light sources. This is really simple and effective. In bright renderings I would avoid too many of those extra lights, though it looks amazing if you have a dark rendering and you create an interesting atmosphere.
If you make a photo-studio rendering remember that with your HDR reflections that are visible on your model, there should be no trees or other outdoor elements visible. Should you choose an outdoor image you can blur the HDR in the HDR Editor. This makes the disturbing elements in your reflections disappear a bit.
If your sky is too blue, just de-saturate it in the editor, maybe not totally though, since a light blue can have a nice effect.
Using the KeyShot tools to edit your HDR images
Changing the background
If you don't want a gradient background, or like the image that your HDRI is creating in the background in your render, you can check the color slot and choose a color that you like as a background. This will not change light or reflections, only the background. Remember that the color will not be reflected on your model.
Changing the background to suit your tastes with the tools shown
Creating light sources
The HDR Edit mode allows you to create light sources in a few clicks. The results are very good, and sometimes necessary. Especially if you have dark scenes and your HDRI is not illuminating the part that you like. In this case it will really help to add a Highlight or Pin to make it a little lighter.
Creating convincing light sources in a few short clicks
The Pin can have a color of your choice ? this definitely makes the scene more interesting. I suggest a very soft bright orange for warm atmospheres, and a bright blue for cold atmospheres. Do not colorize the entire scene with strong colors, just a little touch of color here and there is fine (in my sample there is a strong red, but this is just to show you the setting).
Try to keep your color hues subtle