The default process to shutdown windows 8 is quite lengthy. If you are at the desktop then first you need to go to Start screen, then logout and then in the power option is the shutdown option. It is possible to have a quick desktop icon that can do this in a single step.
Create a desktop shutdown icon
The first thing to do is to create a desktop icon that will shutdown the machine. Simply right click on the desktop and go to New > Shortcut.
In the shortcut location enter the following and save.
shutdown /s /t 0
Now this is the shortcut to shutdown the machine. Next try to give it a good looking shutdown icon. Right click the shortcut, go to properties and click Change icon and select a shutdown icon from the selection dialog.
Add to taskbar and Start screen
Once the icon is saved and ready. right click the icon and click "Pin to Start" and "Pin to Taskbar". This will add the icon to the Taskbar and the Start screen.
Now the desktop icon can be deleted.
Add a restart button
Use the same above process to create a restart button as well. The only difference would be in the command which in case of restart would be
shutdown /r /t 0
This trick will save time when shutting down windows 8.