I always pictured the inhabitants of the Shire in a sort of modified English costume from the mid-18th century, to a degree. Tolkien does describe part of the dress, specifically referring to waistcoats (vests). They do wear cloaks when travelling, too, there are those references. If I recall correctly, too, in "The Hobbit", there is reference to a preference for bright colors.
I think a generation of Tolkien fans got their picture of how Hobbits looked and dressed from the illustrations by the Brothers Hildebrandt. They depicted Bilbo, Frodo and the others as wearing knickers, plain white shirts and their waistcoats, as appropriate to the season.
If I recall, Tolkien's image of the Shire was a romanticized ideal of the English countryside, just before industrialization. In fact, in the next-to-last chapter of "The Return of the King", "The Scouring of the Shire", I think is the title, the destruction and defilation wrought by Saruman's men is another allusion to the spread of industry into the English countryside, and the transformation that it caused.
For the other races of Middle Earth, inspiration came from Germanic and to a degree, Celtic mythology, and again, the images from the Hildebrandts reinforce the picture that many may have. They seemed to use imagery from the time of the Völkerwanderungen, the great migration of peoples from the East into Europe, and into the early Middle Age, to depict Elves, Men and Dwarves.
I always pictured the Riders of Rohan, for example, as looking like mounted Anglo-Saxons, and that was just from the text, without seeing any illustrations. I don't think they were blond enough in the movie.
The first of the movies is closest to the book, I think, and then, with the second and third, Jackson got a little farther from some of the details, though he maintained a good continuity in telling the overall story.
Prost!
Brad
