There are three main types of drawing tools withing Illustrator. The pen (and subsequently shapes), and pencil and finally the brush. I've commonly used the pen and pencil for drawing shapes. Both have there advantages. But what about the third option the Brush. The brush is a little different as you have to make or install a brush shape. You can then use this brush for more complex effects. This will be a quick demo and information about the brush. Its not a tutorial in its self but still very useful.
Step 1) The first step in creating a brush is to have what you want for a brush drawn on your art board. This is a super simple example but it can be applied to nearly anything.
Below i've drawn a couple of illustrator paths using the pen tool.
Step 2) The next step is to pick the type of brush you want to make. Open up the brush palette Window > Brushes press the new brush at the bottom of the palette, select new art brush. You can of course experiment with these values.
Step 3) (Image missing because i'm a forgetful noob). Name your brush, and press ok. You now have your brush.
Step 4) Use your brush, drag along the art board to make your design. Its as easy as that.
You can of course be very complicated (or simple) with your brush.
Things to consider. Not all of the sources you use to create your brush (step 1) will work. You need to experiment. Change the settings about try different types of brushes and different sources.
As well as this if you want to save your brush out you need to select the brush libraries menu (most left button in the brushes palette) and save it out. If you don't do this your brush will only be availble with that piece of work if you don't.
If you want to check out a cool use of brush within Illustrator check out this post by Blog Spoon Graphics. It is a simple design to create a map, but shows you the principles (this post was going to be longer but i'm short on time. I'm going to be using brushes more and more in my designs that I will share with you. One of my favorites is going to be this sites redesign. It is coming a long and it is going to be sweet. I've got plenty of cool ideas.