:NEW: UPDATED:
I've re-created the sample file that was missing, should give you some idea what this is all about. <--HIT DOWNLOAD

An old tutorial request, So I brought it back.
Kinda old, I had to dig it up deep inside my hdd.
I don't have the sample file anymore but the tutorial should be quite easy to follow.

Someone asked me once, why not just use another layer with brush and overlay. That does the job well too but with this technique you can move it around in real time and see how it react across your canvas.

EXTRA INFO: I'm probably using about 7~8 shapes on the Sphere image on the right. They bleed to each other when they are close, so you can create long organic looking highlights too.

If you overlap the shape you'll get stronger/shaper bloom.