In a 2015 Vanity Fair article, The Force Awakens Costume designer Michael Kaplan was asked if he created a backstory in his mind about the evolution of "fashion" in the the galaxy after Return of the Jedi. He answered, "Maybe subconsciously, but with the stormtroopers it was more of a simplification, almost like, 'What would Apple do?' J.J. wanted them to look like stormtroopers at a glance but also be different enough to kind of wow people and get them excited about the new design."
Okay, so got that? TFA First Order Stormtroopers were designed with a nod to the Apple aesthetic.
In a Wall Street Journal article published today, Jony Ive, Chief Design Officer for Apple, was interviewed on a wide range of topics, one of which was his influence/inspiration for Star Wars. Mr. Ive reportedly spoke with J.J. Abrams during TFA pre-production and told him that "he had the look of the original Stormtroopers in mind when he designed Apple’s earbuds."
So, Ive's design for the ubiquitous Apple earbuds was, at least in some part, inspired by the OT Stormtroopers.
Therefore, Imperial Stormtroopers were an inspiration for Apple, whose aesthetic, in turn, was then an inspiration for First Order Stormtroopers.
It almost sounds like a version of the telephone game.
On a related note, an interview with Ive in a 2015 New Yorker article, he explained that he had a conversation with J.J. Abrams about Kylo Ren's lightsaber design. “I thought it would be interesting if it were less precise, and just a little bit more spitty.” JJ obviously applied this suggestion to the film, saying later, “His [Kylo Ren's] lightsaber was as imperfect and unpredictable as the character.”