Do you want to keep the Dock in OS X organized? You can do this with a blank space. This way, you can divide your Dock in different groups. Copy and paste the following command in a Terminal window. After the restart, the space will be added to the Dock, which you can move to any place.
OS X: How to quickly hide the desktop icons
Do you often have to do a presentation on your Mac and don’t want others to see what’s on your desktop? It’s possible to quickly hide the icons on your desktop. Launch Terminal and enter the following command.
Disable ‘Preferences’ menu option in OS X Finder
It is possible to disable the OS X Finder menu option: ‘Finder ▸ Preferences’ (cmd⌘ + ,). This will prohibit setting changes in the OS X Finder application.
How to reset the DNS cache in OS X
OS X always keeps a local cache of resolved DNS queries (IP address) for future reference. But sometimes it may be necessary to clear (flush) the cache. You can do this with a terminal command, this will refresh the local DNS cache.
Disable ‘Stay on front’ for OSX help windows
When opening the help window in OS X, the window will always open and stays on the front. This can be very frustrating, so you can use the following command in Terminal to get the help-center window behave like all other windows in OS X.
Finder: Disable ‘Go to Folder’ menu option
Disable the menu option: ‘Go ▸ Go to folder’ in the Mac OS X Finder menubar.
E-mail photos from iPhoto with the mail application
When you send an image from iPhoto through an email, you can do this with the built-in mail function. Here you must use the email templates. With the following command you can disable this behavior and send pictures through the mail application and immediately create a new message.