See, for me, i got the exact opposite way. My homebrew campaign setting is set in earths equivalent of 1050 - so its pretty low tech, few cities and almost no towns, mostly it's little manors and feudal areas, and wilderness. I reference alot from the book From Stone To Steel - it's an awesome hardcover which goes back to the stone age through to the end of the Renaissance (ugh, i haven't spelt that one for awhile, so don't hold me to that). It has guns, and many, many other things too. Roman Armours, African throwing axes, Middle Eastern swords, etc etc etc - all chronilogicalized too.
So i refer to it alot in regards to 'hmmm, does this fit in this era?' or 'would this ____ be in this pseudo-germanic country, or not?' etc etc. I like gritty, edge of civilization, dark heroes. They can shine, but they won't be perfect. Nore are they super-heroes like in standard D&D - my campaign is low magic, and i am drawing a lot off of Iron Heroes for mechanics here.
I draw off alot of inspiration from Tolkien (who doesn't,

) but even moreso than most. Since i am a straight-up medieval fantasy, a genre which tolkien perfected, if not created, i refer to him first and real world concepts second, and keep my opinions to myself. For example, my dwarves are Tolkien-esque, not nordic dwarves, and as such, they are distinct. I wanted to have subraces (similar to standard D&D, but cmapaign specific, obviously) but i'd rather keep to Tolkiens themes.
As for the real-world concepts, i go staright to the bible tales, greek myths, and nordic sagas for them. My Berserker class replaces the barbarian, and i am adding in many cletic monsters at the moment, mainly 'cause i am going through my Oxford celtic dictionary at the moment - all of which are based off to be as close to the original in theme and mechanics and power as possible.
Anyways, just a few details of my way fantasy gaming. Good'ol FR is always nice for a change-up when you need some high-magic, high fantasy gaming.