If you’re like me and have quite a few applications in your Dock, you have probably thought about organizing them. Luckily, the solution is already built into your Mac and your Dock could be organized in seconds.
- Open up Terminal (Command + Space: Type in “Terminal”)
- Paste this line of code:
You should now have a transparent spacer in your Mac’s dock that you can rearrange. Add as many as you want.
Source: Lifehacker (http://lifehacker.com/5993307/easily-add-spacers-to-your-macs-dock)