Making the Light Streaks preset: long-exposure motion blur in the browser
Light Streaks is inspired by the motion blur trails you get at slow shutter speeds. It's built almost entirely around the Motion Trails effect, with a few layers around it to shape the look. All in a browser tab.
Start with Contrast
Take an image with decent contrast.
Then push it further with Curves: highlights more pronounced, shadows deeper. The streaks will come from the highlights, so the more they stand out, the better.
Add Motion Trails
This is the main effect. It creates an animated shift of the highlights.
Crank up the threshold knee to control how much of the image gets picked up and make the effect more pronounced. Direction can go anywhere: top, bottom, diagonal. Here it goes to the left. A slight shake makes the movement feel more handheld. Blending mode goes to Lighten, so the trails appear on top of the original image.
Two Layers of Motion Blur
Now add two Motion Blur layers with slightly different directions. This emphasizes the motion and makes it less uniform. The first one blends as Normal, the second as Lighten - extra smooth blur, very soft image.
Balance the Contrast Back
All those trails add a lot of light on top, and that kills the contrast. Add Curves again to bring it back.
Push the Colors
Once the tones feel right, add a Color Grading effect: push some colors, do some tone splitting. The idea is to give the streaks slightly different shades along the way. They start light, then shift into a different color, which makes the whole thing look more painterly, almost like brush strokes.
A Starting Point
You can experiment further from here. Add print artifacts and similar effects work very well on top. A few images with the preset applied:
Try it yourself: open the Light Streaks preset.