Simple Orb:
Create this just by using blending options:

1.Open up a new document,any size is good for this tutorial.
2.Do an elliptical marquee tool as shown.

3.Fill with the color #38B549
4.Now Layer>Layer Style>Blending options and use these setteings.




now you should have this or something like it

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After messing around with this a little bit you could have something like this.Just try Duplicating layers and changing blending modes.Also mess with some filters.I dont wanna give all the secrets away or you wont have fun learning this stuff.

you can also make smilies with this orb.