This is a rather complicated tutorial. i would not recommend it to beginners to photoshop but i have made it as detailed as possible so that it could be understood by anyone!
Step1: lets start out by making a new document (200x200). fill the background with a dull color like 6B6A5E, then create a new layer. select the circle marquee tool. towards the top of the screen you will see a style menu for the marquee tool. in that menu select fixed size. next to that menu you can define the size. for the height and width enter 120px . on your new layer select an are (circle should show up when you click) then fill it with another color. i will be using 9B9A8D .
Step2: now right click on the orb layer in the layers palette and select blending options. a window will pop-up. in that window on the left hand side select inner glow (checking the box as well). in the inner glow options make yours the same as below your results on the right:
Step3: on your toolbar palette double click on your foreground color (one on top). select a color in the area like below the color i have selected is F5F3D7:
Ok now you have your new color selected. create a new layer above your orbe layer. in the layers palette select your orbe layer then ctrl+click on the new layer. this should make a circle selection (left image). now select the new (blank) layer while keeping the circle selection. (left image). select the gradient fill tool w/ the radial gradient fill (top menu bar). while holding down shift from the center of the selection drag it to the top of the selection (right image)
Step 3: with the circle area still selected make yet another new layer. select the brush tool (100px) and in the top menu for the brush option select:
mode - soft light
opacity - 100%
flow - 3%
Then fill in a small area of the orbe at the bottom till you find something that you like. below i have my before and after:
Step 4: make another new layer with that circle area still selected! with the new layer selected in the layer palette go to select > modify > contract and enter 3 for the value. this will make the selection a little smaller. now after that select the gradient tool with the radial gradient again and drag from the top of the selection to the bottom (while holding down shift to make straight line) left image is the process right is the result:
More Tutorials: 
