Okay...For e.g you can compose an email with your formatting signature logo date timestamp etc then

1)Select All
2)Go to Insert Tab
3)Click on Quickparts
4)Scroll down and "Save selection to Quickpart Gallery"
5)Enter the name,gallery,category,description,savein,options
6)In Gallery you will select "Autotext , footers, headers, ........and Quickparts"
7)select Quickparts.
8)In Savein Select "Normalemail"
9)Options: based on your requirement.

So if you see there are almost 9 to 10 steps to add one quick part or you would building block...but when u right click on a quickpart and select "Organise and delete" ...we will be able to see the preview but wont be able to edit it directly...