Creating Custom Shapes
First open the picture you want to use as a custom shape in Photoshop. I am using a clipart image I got from Microsoft Office shown below:

To create a shape in Photoshop we will make it a brush. First we need to name the the brush. On the Standard Toolbar select Edit > Define Brush Preset:

Next assign the brush a name:

Click OK to close the Brush Name dialog box. To save my brush permanently we need to take one more step otherwise when you load a different brush set your brush will be lost. To save your brush permanently, click Edit and select Preset Manager:

At the Preset Manager dialog box select Brush as your Preset Type, then select the brush you just saved from the drop-down resets list. (Reminder: Press Ctrl + Click to select more than one brush.}
Click Save Set. In the Save window, browse to select a location for the brush set, the default folder for Photoshop Brushes, enter a name, and click save.

Close the tree trunk clipart and return to your house project. Close this window and return to the drawing tutorial.