Here's a before and after look using our BSI set and the Jax textures from Daz3D (the morph is Legacy Darius plus Legacy Gianni 6).
Here's how you do it!
1. Open your rendered image in the GIMP.
2. Click on the Filters menu option, then Light And Shadow.
3. Choose Lens Flare or Gradient Flare. Gradient Flare has a lot of different options where Lens Flare is much simpler.
4. A dialogue box pops up. For Lens Flare, just click the point in the preview where you want the lens flare to go, and then click OK.
5. For Gradient Flare, pick a flare option from the Selector list, click where in the preview you want it to go, then go to the Settings tab.
6. The Radius lets you determine how large the flare is. Hue rotation determines the color. Vector Angle and Vector Length determine where the "arm" of the flare with its bokeh will point and how long it will be. Click the preview where you want the flare to start and play with the sliders until you get a result that you like.
7. In the demo, the top right pic shows the plain Lens Flare. The bottom right shows the "Distant Sun" option with its yellow color and medium radius. And the "Gflare x3" option shows what you can do by repeatedly layering some different flares.
Have fun with it! I look forward to seeing what you all can do with this quick, easy and fun form of postwork.