It's an interesting question, yet one I try not to dwell on very often because it can be stagnating, almost like a writers block.
I'm with you on studying other films and designers work for inspiration, or merely coming across something cool by chance when not even trying to pay attention. But from there, designing is an intuitive process that comes from the gut for me. Being a believer of the "take what you like and leave the rest" mindset about sound design concepts, I usually have chosen to take away from these films abstract concepts rather than micro-detail techniques of a specific type of sound.
Two examples that come to mind for me are:
- Inception: In the 1st dream level location when Eams opens the warehouse sliding door for the cars to drive in, I noticed in the mix all you can hear is this tasty, unique screech sound, and not really the door handle/latch itself. What I took away from this and have since used is that squeak and creak elements can help sell a door that needs to cut through the mix no matter what, and to give doors a unique creak/squeak element that has some character rather than the over used 6000 Series-style squeaks. Of course I don't squeak every sing door, but I try to find some unique character element to give the door a signature sound beyond the generic "ca-chunk" a rattle, or a screech, or a stress groan, etc - it all sprouted from seeing a specific sound moment in this film.
- Transformers: If there's any film that's a Ph.D in flutters, this is it. It opened me to a new world of playing with flutters in my sound palette. Not because I wanted to create something exactly like the film had, but, I liked how flutters sound sexy, powerful, and even frightening when designed appropriately. It opening me to something new to add in my pocket of design tricks. And what I took away from this film was the concept of working with Mondo Mod, and making all sorts of flutters at different speeds, speed ramps, and with different source material beyond air whoosh. sounds, reversing them to create suck-in flutters, etc. While Transformers used flutters to help sell the massiveness of the robots, one of end results of embracing this concept was a scary-sounding (admittedly, I get goosebumps every time I play over it in the edit) vocal flutter design for a film I'm working on - a complete different direction from the source I studied, but still related in the abstract.