Fontforge: How do I create stylistic set?

I'm working on developing an understanding of stylistic sets. I'd like to include them in the typeface I'm designing. 

As I understand it, in Creative Cloud software, the user goes into the Opentype window, highlights a block of text and selects a stylistic set. That stylistic set then applies select alternate characters throughout that block of text. It doesn't sub in an entirely new character set but selects a handful of alternates substitutions.  

I've searched for a tutorial on how to do this through the Fontforge interface with no luck. Is it possible to program a stylistic set through the Fontforge UI? I'm guessing it is a lookup containing a set of single substitutions? My understanding overall of lookups is somewhat weak and I haven't learned how to code the back end of my fonts. I'd probably need a walkthrough.

Any help is much appreciated!