new document

Make a new document. I used 380x380. Fill it in with black.

apply Filter-Lens Flare effect

Go to Filter>Render>Lens Flare and use these settings:

Make sure you try and center it as much as possible. This is what I worked with:

apply Filter - Shear effect

Now go to Filter>Distort>Shear and use these settings:

add different color

Now you got something like this:

Press CNTRL+U and apply these hue settings:

Feel free to explore a different color. Try not to use a lot of saturation.

apply Color Dodge

Duplicate the background layer and apply Color Dodge to the top layer:

Transform

Duplicate the Background Layer again and go to Edit>Free Transform:

Now you got something like this:

duplicate and repeat

Now all you do is duplicate Background copy 2 Layer (the one we just made in step 6) you repeat rotating it 90CW. The you repeat again untill you have this many layers:

You should now have something like this:

resize it into a avatar size

Ok now lets resize it into a avatar size, for example 100x100 120x120. Go to Image>Image Size and put in the height and width that you want to use for your avatar. Once you shrink these large lens flare bursts they seem to merge together and create a killer effect!
Here are examples of different sizes I used: