1. Create a new Illustrator CS5 Web Document (624*351px) . Select the Line Segment Tool ( \ ) and holding SHIFT draw a straight horizontal line.
2. Apply a colored stroke on this line (simply press X to switch from fill color to stroke color and choose a color from the swatches panel). Having this line selected go to Effects -> Distort & Transform and choose Zig Zag. I have used a 35px absolute size and 4 ridges/segment. Make sure "corner" is checked.
3. Here's where CS5 comes handy. We'll use the new CS5 feature called Width Tool (SHIFT+W). Width the Width Tool selected grab the left point of the line and strat draging up to make the "tail" of the lighting thicker.
4. That's all, you got a ligthing shape :). In the next steps I'll show how to colorize it. First you have to Object -> Expand Appearance having the line selected. Now we'll apply a orange->yellow gradient. Select the shape and apply a gradient in the Gradient Window (CTRL+F9). I won't give you the exact colors I've used because you need to experiment yourself and find the colors you like the most.
*Note that I have also added a rectangle as a background with black->dark gray background.
5. Make a copy of this layer in the layers panel. Select the bottom layer and go to Effect->Path->Offset Path and choose 4px, Miter joins. Expand this layer and apply a darker gradient than you did on the first layer.
6. Using the Pen Tool ( P ) draw some white reflections over the top margins of the bolt.
*I have also added a subtle pattern from the Pattern menu, by duplicating the top layer, choosing pattern and lowering the opacity.
7. The final step is to add some shadows using the Ellipse Tool ( L ), with a 100% opacity black -> 0% opacity black gradient radial gradient.
The main point of this tutorial is to show that in Illustrator you can easily create different shapes using only primitve shapes and some effects/tools (in this case Zig Zag effect and the new Width Tool).
I hope you enjoyed this tutorial , and feel free to post any question in the comment section below or tweet @tips4designcom .