In the following tutorial, I'll show you how to create a glowing light abstract vector graphic. The great thing about this tutorial is it doesn't use any raster effects. The final illustration is all vector! In this tutorial, you'll utilize blends, different blend modes, and gradient meshes. Moreover, these techniques are real easy to apply to other illustrations.
Create a new document that is 8 inches wide by 11 inches tall. Use the Rectangle Tool (M) and create a rectangle the size of your document. Fill the rectangle with a rich black (I used these CMYK values: C=100, M=100, Y=100, and K=100).
With the Mesh Tool (U), click on the rectangle about an inch from the top in the center of the rectangle.
After you add a mesh point with the Mesh Tool (U), change the color of the mesh point in the Color Panel to a dark blue (C=100, M=40, Y=0, and K=60). If you have accidently clicked away from the mesh point, use the Direct Selection Tool (A) to select the mesh point.
With the Mesh Tool (U), create another mesh point in the center of the rectangle. Try to keep it in line vertically with the first mesh point.
Change the color of the second mesh point to a dark red from the Color Panel (C=0, M=100, Y=100, and K=50).
Add another mesh point about an inch from the bottom and change the color to a dark orange (C=0, M=80, Y=100, and K=30).
In the next couple of steps we're going to create a brush for the glowing lines in the illustration. With the Rectangle Tool (M), create a rectangle that is 4 inches wide by .125 inches tall. Fill it with a 5% black.
Copy (Command + C) the new rectangle and Paste it in Front (Command + F). Change the height of the copied rectangle to .03 inches and fill it with white.
Select the first long rectangle and change the transparency to 0%. If it is getting hard to see the rectangle, you can place them over your Gradient Mesh so you can see what you are doing.
Select both rectangles and create a Blend by going to Object > Blend > Make. Now the line should look like it is glowing.
Select your blend and drag it into the Brush Panel. Then choose New Art Brush from the options. Keep all the default Art Brush Options the same. We're done with the blend and you can set it aside or delete it.
With the new brush we can start creating the vertical lines. I have a Wacom tablet so it's really easy to use the Brush Tool (B) to create smooth flowing paths. If you don't have a Wacom or don't feel comfortable using the Brush Tool (B), you can always use the Pen Tool (P) and apply the brush to the path. Decide which tool you want to use and create your first flowing line down the middle of your gradient mesh.
Select the new line a choose Overlay for the blend mode in the Transparency Panel.
Draw three to five more lines overlapping each other and set to Overlay.
Next, draw three to five more lines, set to Overlay, and change the Stroke Weight to .5 pt.
Again draw five to ten more lines, set to Overlay, change the Stroke Weight to .25 pt, and set the Opacity to 20% from the Transparency Panel.
Draw three to five more lines, set to Overlay, change the Stroke Weight to 3 pt, and set the Opacity to 35%.
The lines are done and now it is time to add a little more glow to the illustration. First create an ellipse with the Ellipse Tool (L) that is .5 inches by .5 inches. Change the color to a 8% yellow.
Copy (Command + C) the ellipse, Paste it in Front (Command +F), scale it down to .25 inches by .25 inches, and change the fill to white.
Next change the Opacity of the first ellipse to 0% from the Transparency Panel and blend the two ellipses like the brush we created.
Place the blended ellipse over the line where a couple of them converge and set the blend mode to Overlay.
Copy (Command + C) and Paste (Command + V) the blended ellipse around other line converging areas in the illustration. All done!
Below is the final image again. These techniques can easily be applied to many other illustrations, it just takes some experimenting!