“Smooth” refers to how the present value compares to the past and the future.
We are 3.5 dimensional creatures crawling through 4 dimensions - we have no access to the future, so we must smooth using past data.
There are a bunch of techniques on that page, and it depends on how “responsive” you want it to be. Adding half the difference between current and previous value could be the simplest thing that could possibly work.
As an alternative, you might find that the physics system on the pawn can simulate an “intertia” that dampens erratic inputs, creating the illusion, of the illusion, of smoothing 
I think a more specific answer depends on the genre and personal preference through experimentation.