1.For this tutorial you can use a project of your own, but I will just make a new image, 300x300 px.
I will create a simple form here, you may again use your own work. The form must be filled with a
light color, for example I used a medium blue:

2.Now create a new layer above the form you use. Set its blending mode to Color Dodge. Now select the
brush tool and set the brush to one of the brushes we made in my (link)brush tutorial(/link). Now click on the
upper red circle you see below to access the brush options and select its Spacing to around 150(the second red circle):

After that make some strokes. then select Filter->Blur->Motion Blur with 35. You must have something like this:

3.Now create a new layer with Overlay Blending. Make fewer strokes with the same brush and color. Then press
Ctrl+F (this will call the last used filter, in our case Motion Blur with 35). Your image must be something like this:

4.Now Create a new layer, Color Dodge blend mode. Select yellow and make some strokes with the brush.
Ctrl+F it! Create again a new layer with Overlay blending and again make a few strokes, this time set the
opacity to around 50 without blurring the layer. Your image should look like this:

That's the base of the tutorial, you can use brushing until you achieve the desired effect! Look what I have made
here: