For me, it was stumbling on forums like this one and LAH.com back in the mid-2000s, and dedicated story pages like TrishTales. Written by Kinja, an avid contributor of LAH.com, TrishTales followed the adventures of its titular character, avid shoeplayer and shoe-loser Trisha Kendrick, throughout college and out into the working world. The stories involved her losing a shoe somewhere somehow in some humorous fashion(and not always getting it back

Trisha wasn't the sole (get it?) inspiration for my Two Stephanies Stories; in fact, there were parts of her personality that run completely opposite to my main character Steffy. For example, although both women work in banks and love playing with their shoes, Trisha loathes wearing nylons because it makes keeping her shoes on more difficult whereas Steffy loves wearing nylons for that very same reason. In addition, Steffy is more disciplined when it comes to keeping track of her shoes; she rarely ever loses them and never for very long. Furthermore, Steffy is more flirtatious with her shoeplay; she not only does it because she likes it but because she knows men and some women(more than whom would care to admit it) like it too, but Trisha on the other hand is for the most part oblivious to the attention her shoeplay and shoe loss garners. Trisha has many pairs of shoes (mostly mules and clogs) while Steffy's has many pairs of nylons (mostly pantyhose and tights). Lastly, Trisha is a little shy and reserved--and straight--but Steffy is a lesbian and more extroverted.
In part, you could say, my Two Stephanies stories take place in a parallel universe to The TrishTales universe--same Earth, different scenarios. I'd like to know what you guys think about this, so drop me a reply with your own theories.