Firstly find a subject to base the flowing light streams on. I picked out an image of a drinks can.
Using the Pen Tool draw a path around the object, make the selection and paste into a new document using a black background.
Reselect the object by CMD/CTRL + Click on the layer, go to Select > Feather and enter 1px. Inverse the selection and hit delete.
Duplicate the layer and set the layer style to Multiply, drop the Opacity to suit.
These tips help the object blend with the background a little more realistically by erasing out the hard edges and altering the lighting and shadows.
On a new layer draw a circular marquee and add a Gradient fading to black with a colour of your choice, here I've chosen a cool green.
Transform the gradient and squash it vertically to add a little perspective.
Open up some kind of texture and paste it into the document. This particular image is a watercolor texture from the GoMedia Freebies. Desaturate to remove the colour.
Change the blending mode to Multiply to render the white areas of the texture transparent.
Back on the can or object layer add an Outer Glow through the Layer Styles, the key is to change the blending mode to Color Dodge to give a really intense glow.
Prepare a brush for creating the flowing light streams, experiment with the brush settings to give a thin tapered stroke. The main option to adjust is the Control and Minimum Diameter settings in the Shape Dynamics section.
Use the Pen Tool to draw a smooth flowing path, with the Pen Tool still selected right click and select Stroke Path, ensure the Brush option is selected along with Simulate Pressure.
Add another Outer Glow to the layer of the brush stroke using similar Color Dodge settings.
Draw as many streams as you like around the object, keeping the lines flowing as smoothly as possible in a variety of directions.
The Color Dodge effect works the best when the objects overlap the coloured gradient, here I scale up the gradient to allow for more light effects around the object.
Unfortunately the straight edges of the texture layer show through, use a large eraser to blend them out.
Add a little atmosphere to the object by placing a few blobs of colour on a new layer. Changing the blending mode to Soft Light will give a slight green glow to the object as if it is reflecting the green light from the intense glowing lines, overall adding a little more realism.
Make a selection from the object layer, inverse and delete out the unwanted area.
The light streams look okay flowing out from underneath the object but they would look a little better if they interacted in some way. Move the light stream layer above the object.
Erase out the majority of the lines leaving select areas which blend into or around the object.
A common addition to this trendy style is an array of glowing light particles. Setup another brush, this time play around with the Scatter, Spacing and Size Jitter options.
Brush in a range of dots and blobs with varying brush sizes to cover the whole of the object and flowing lines. Add the same Outer Glow layer style as the light stream layer.
Erase out the most of the particles to leave a subtle effect with slight differences in opacity.
Finish off the image with a few focal rings on multiple layers with very low opacity. These help relate to the objects that appear when photographing light with a camera, adding a little extra realism.
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