Here is the tutorial for making a brush in Photoshop.
Photoshop
Level - Easy
Step 1: Open Selected Picture
Open the picture you would like to make into a brush.
Step 2: Adding Greyscale
Next go to Image / Mode / Greyscale
Step 3: Selecting Part of the Picture
Choose the Lasso Tool and use it to select the part of the picture you would like to use as the brush as seen in Figure 03.
Step 4: Define the Brush
With the part you selected go to Edit / Define Brush
Step 5: Select the brush
Now go to the brush list and select the brush you just made and you’re finished.
