Okay, I'm assuming you've read the pervious tutorial on the basic creation of brushes, setting dynamics etc. Now let's take a look at a more specific example of creating your own brushes, in this case for fur or hair.

Create the shape
First we need to create the actual tip shape for our fur brush. So here I've drawn (with a tablet and pressure sensitive brush) some quick fur or hair. Next of course we have to turn it into a brush. As covered in the pervious tutorial you do this by selecting it with the Marquee tool, going to the edit menu and clicking "Define Brush". I'd probably name this brush "Fur Temp" or something as it's not the finished version and will eventually be deleted.

Setting the brush up
So now we want to go into the Brushes menu and take a look at our brush:

As you can see it needs some serious help! So here's what we're going to do:

1. The first problem is that the fur should really be spaced farther apart. So in Brush Tip Shape I'm going to take the "Spacing" setting up to around 70%. This helps to separate clumps of fur.
2. Next we need the fur to vary in size etc. This is called "Jitter" and is the amount something varies on a brush. So in Shape Dynamics I'm taking the "Size Jitter" up to around 35% and making sure it's set for "Pen Pressure".
3. Also in Shape Dynamics there is an "Angle Jitter". The higher this is the more random the angles of the brush will be. I don't want the fur to be too messy, but I also don't want it to all look the same so I'd set this around 5%.
4. At this point the brush shape in the preview will look something like this:
5. Now we're ready to really make the brush more random, though of course depending on the kind of fur you want to create you may want to skip this step or make these settings more or less. So I'm going to go into Scattering and adjust the settings there to scatter the fur, maybe take the count up a little (creating more clumps). This results in the brush preview changing a lot:
6. Lastly, make sure to check the Other Dynamics box so your brush properly fades at the end. Then you will want to click the "Create New Brush" icon in the lower right corner of the brush window to save your brush. I named my "Ryn's Fur Brush #1". You can then delete the original brush (the temp one) as you have one now with proper settings.

Painting with the Brush
Now you're ready to try painting with the brush...

In the last (lower) example shown above the brush us used with white over the darker colors, and also (and this is KEY!) the ANGLE of the brush is adjusted to paint the fur going on the other direction. To do this just go to your Brush Tip Shape menu and rotate the brush using the handles, or by changing the angle as shown here:

This allows you to paint fur following the shapes of animal faces, bodies etc.

A Few last Tips...
As you've probably guessed by now you can create a whole number of different looks of fur or hair by creating different brush tips, and adjusting their size, jitters, scattering and so forth. As shown in the example below you can create softer looking fur by just making the brush smaller.

Lastly if you want to create MUCH softer fur such as the lower right example above you can use the "Smudge" tool on it afterwards. )The smudge tool is the one that looks like a finger painting). You can use brush shapes with the smudge tool too! So in this case I used the same shape, but I turned scattering off (otherwise it just blurs everything).

I hope you've found this quick fur tutorial helpful and will experiment with brushes of your own!