There is a nice plugin for WordPress which makes creating pull quotes a very simple task. It is called Simple Pull Quotes.
For installing it
1.In Admin area of WordPress, under ‘plugin’ tab, click “Add New”
2. In the search box, write “Simple Pull Quotes”
3. You would come across something like this
4. Install and activate.
Open your visual editor and write your post as usual. Select the text you want to come as pull quote and look for button as shown below. Press the button and the selected text would automatically be displayed as pull quote.