I have included a tutorial for this question below, the radial menus are very quick to use especially as you do not need to wait for them to appear to access each function simply memorize the correct button and movement of the mouse to get quickly to any common function
Radial menus are small icons that appear surrounding your cursor location, each icon can be customized to your most used features these menus allow you to quickly and easily access features instantly with a click and swish of your mouse.
To access these menus open any version of NX from 4 - 8.5 and click Tools> Customise
Scroll to the bottom of the list to locate options for radial menus 1 to 3, to customize each menu tick the box to the left of the heading.
With the first menu up and in customize mode drag your most used features from the main menu bar into one of 8 spaces available in the radial menu. I find that horizontal and vertical positions the easiest to access so put the most frequently used functions here.
All three radial menus can be customized this way, I use each menu for a different set of tools E.g 1. Basic modelling, 2. Sketching 3. Synchronous tools.
The menus are accessed in NX by using the first second and third mouse buttons in corresponding order
In order to utilise the menus the 1st (left click), 2nd(Middle wheel click) and 3rd (right mouse click) must be completed while holding down Control and Shift. To make this process easier I assign Ctrl and Shift to a button on my Space Xplorer 3D mouse making it very easy to instantly access any function.
It is also very important to point out that you do not have to wait for the menus to appear to access the functions a smooth (Ctrl, Shift) click and drag movement will bring up the selected functions instantly.
The screenshot below shows the first radial menu activated with the first mouse button click, functions such as set display part can save alot of time in scrolling through menus to the required line.
This method of choosing functions can also free up alot of valuable real estate on the screen clearing the majority of the large bulky icons that make up NX's GUI.
NX also has a 4th radial menu that can be accessed by simply holding down the right hand mouse button this menu however is not easily customizable and requires the editing of a pop up menu file to do, however its default settings of different model views I find very useful and by far the easiest way to switch from wireframe mode to solid etc. with a simple click and swish.
Further menus are also available as an on context right hand mouse click I.E when selecting different parts these menus can be an easy way to edit with rollback and delete.