If you don't feel like designing your own dock, you download a super cool one for free from LeopardDocks. If you do this, you don't need Gimp or Photoshop.
Software you need:
A photo-editing program such as Gimp or Adobe Photoshop
Swap my Dock
Step 1: Design Your Dock!
Make it crazy! Use lots of colors and various degrees of reflectiveness.
Take your time.
Test out your dock, then make changes and try it again.
Don't use all straight lines or all curves, mix and match.
If you need inspiration or want to see some awesome docks, check out LeopardDocks.
Step 2: Save Your Dock.
Remember where you saved it!!!
Step 3: Turn Your Design Into Your Real Dock
If SwapMyDock rejects your dock design:
Make sure your dock is the right size (1000 by 75).
Make sure your dock is named scurve-m
Make sure your dock is a .png.
If it still doesn't work, send me a message or post in the comments.