Here's how I did the light rays. You can do them in the image you're working on, but I created mine as a new image:

1 - open a new layer. Fill with 50% gray:

http://www.pbase.com/pam_r/image/85561132.jpg

2 - Go to Filter>Noise>Add noise and use these settings:

http://www.pbase.com/pam_r/image/85561139.jpg

3 - Go to Filters>Blur>Motion blur and use these settings (for larger sizes you will need to run the filter again by hitting Ctrl+F until you get clear lines). Ctrl+F applies the previously used filter again (very handy to keep in your list of shortcuts):

http://www.pbase.com/pam_r/image/85561142.jpg

4 - Now to give some shape to the rays. Hit Ctrl+A or Select>All. Then Ctrl+T to enter Transform mode. Hover your cursor inside the bounding box and right-click to pull up the transform options. Choose "Perspective". Or, you can go to Edit>Transform>Perspective:

http://www.pbase.com/pam_r/image/85561145.jpg

5 - grab a bottom corner handle and pull out. Grab a top corner handle and push towards the middle to get a shape similar to this:

http://www.pbase.com/pam_r/image/85561150.jpg

6 - Copy the rays (Select>All, Edit>Copy merged). Paste into your image (Ctrl+V) and move it into position. Add a layer mask, invert the mask (Ctrl+I), then paint white to reveal the rays:

http://www.pbase.com/pam_r/image/85561152.jpg

http://www.pbase.com/pam_r/image/85561156.jpg

7 - Blur the rays to your taste using Gaussian blur. Experiment with blend modes. Screen, Soft Light, and Overlay are good starting points:

http://www.pbase.com/pam_r/image/85561168.jpg

Have fun!

--
Pam
http://www.pbase.com/pam_r
'art is working on something 'til you like it...then leaving it that way'