Making your own brushes
Step 1: Open your Adobe photoshop then make a new 500×200 document or whatever size you want. File » New.
Step 2: Draw anything , I drew a hearts then go to Edit » Define brush.
Screenshot: - Larger screenshot here.

Step 3: Then you're done! It's so easy right? ^^
II. Using your brushes.
Step 1: Go to brush tool at the left sidebar, or find this tool > 
Step 2: Then open the brush preset picker. Then find the brushes you made. Here's mine:

Done! <3

