Summary
In many competitions, contestants can perform "freestyle" maneuvers of their own choosing. These elements give competitors an opportunity to do things that most others cannot. In Olympic events, we routinely see difficulty values assigned to optional elements in figure skating, slopestyle snowboarding and gymnastics.
In LiveJudge, we allow administrators to create a library of custom freestyle elements/maneuvers, each with its own label, description and difficulty element.

Sample freestyle library with 3 elements. You can have unlimited elements.
How You Offer Possible Freestyle Elements to Your Contestants
Once you create a library of freestyle elements, you can return to judged elements and create (or modify) elements called, say, "Freestyle #1" and "Freestyle #2" (or whatever you want to name them). When you return to the judged elements library to create a freestyle element, the system will prompt you to assign possible freestyle elements that the contestant can choose when entering a class that contains either Freestyle #1 or Freestyle #2 (or both).

For my Freestyle #1 element, I will permit contestants to choose from 3 possible freestyle elements.
How Contestants Choose a Freestyle Element
When entering a class, the competitor will see a freestyle chooser made up of the freestyle elements you elected to offer them above.

Contestants may choose their own freestyle trick

Freestyle chooser. Notice the custom option.
Custom Freestyle Elements
In your judged element setup panel, under the Freestyle Options tab, you will see the ability to switch on "Allow Custom Freestyle." If you do, contestants will see your list of default freestyle selection options (in yellow) and a new option that allows them to describe their own freestyle option (see below).

Admin setup screen to allow custom freestyle definitions by the contestant.
When the contestant goes to define the custom freestyle element, they can only insert a title and a description. Only the HEAD JUDGE for that round can enter the K-element.

Contestant view of the custom freestyle entry panel
What the Head Judge Sees
The head judge will see a yellow K-element box with a ? in it signifying that the contestant has selected a custom maneuver and is now waiting for the head judge to assign it a K-element.

Head judge sees a missing K-element. Uses the "Freestyles" button to open the custom element and assign a K-element.

The head judge can assign a K-element. Judging can now begin for this contestant in this round.
Admin Adjustments
Once the head judge enters and saves the K-element for a custom freestyle element, all judges can commence scoring. After that, the only way to adjust the K-element is to visit the Scoring Admin section of the website and enter a new K-element. Only site admins can do this.
K-element Display
For pre-defined K-Factors and custom ones with assigned K-Factors, all judges will notice that the possible score for that judged element will exceed the total possible points (e.g. 10) provided the K-element is higher than 1.0. This is precisely the point of the difficulty element; if the contestant executes the maneuver perfectly, they will get a 12.5 (in our example below) which accounts for the extra difficulty in performing such a maneuver.

Judge's view of a freestyle element with a defined K-element