Duplicate this dot-layer (Cmd /Ctrl+ J or Layer > Duplicate Layer) and resize it (Ctrl/Cmd+T or Edit > Free Transform) that it was a little more than sphere.
Create a new layer (Cmd /Ctrl+ Shift + N). Take a Brush Tool (B) (Size: 1400px, Hardness: 0%, Opacity: 100%, Color: #0d7ad7). Make a dot in the upper part of a sphere.
Set to this layer Blending Mode: “Color Dodge”, Opacity: 52%.
It’s time to lightning! Load lightning brushes in Photoshop (if you do not know how to do this, use search:)) Create a new layer below previous layer. Take a Brush Tool (B). For each brush size remains the original, Opacity: 100%, Color: #ffffff. I used brushes: 4,13,17,24.
Change the angle of each brush so that it matches the side of the sphere. On one side these brushes have a light area, try to place a light area under the sphere. Apply the brush dot and in different places.
Add a little glow to this layer. Go to Layer > Layer Style > Outer Glow… Make settings like shown in the image.
Here is my result. I combined all the layers with the background in one group “Interior”.
Create the main lightning. Create a new layer (Cmd /Ctrl+ Shift + N). This layer must be the uppermost and not in all of the groups.
Take a Brush Tool (B). Brush size depends on the distance from the central sphere to the lateral spheres. Angle is set in line with a side of sphere. Set Opacity: 100%, Color: #ffffff. Dot draw lightning. To make them more vibrant press in one place several times.
Try to make dynamic lightning. Do not draw them into one plane. Try to make the visibility of volume, putting lightning further the edge of the sphere. Put a very little lightning at the sphere.
Let’s create exploding lightning bundles (“exploding lightning” brush). Create a new document (File > New or Cmd /Ctrl+ N).
Create a new layer and delete the background layer. Set the foreground color to black (D). Take a Brush Tool (B). Use a variety of lightning brushes (I used numbers 1, 7, 19, 20, 21), but rotate them so that their ends converge at a single point. Change the brush size to not get the same type. (Size 100-300px, Opacity: 100%). You should get something like this.
Take a soft brush (Size: 250px, Opacity: 50%, Hardness: 0%) and draw a point in place where center of all the lightning’s.
Now create a brush – spray. It gives the sparks effect of lightning’s. For the base, I take brush “Airbrush Soft Low Density Grainy” in the standard Photoshop brushes. Follow the images and create a brush. Do not forget to save the resulting brush! If you have another brush with a similar effect, you can use it, or add in this brush something else. This is just an example of creating.
Once you create it, set Size: 10px, Opacity: 10%, Hardness: 0% and draw it to lightning near the center and on the edges of lightning as shown. Draw black only.
Go to Channels panel. Hold Option/Alt and click on RGB channel to select all. Invert this selection to select the entire brush (Cmd /Ctrl+ Shift + I). Now save it as Brush Preset (Edit > Define Brush Preset…). That’s it! Now on the Brushes panel you receive this brush.