All other specific reference to primary sources from Tolkien’s writings aside, I have always felt that it makes sense for the elves to wear a really streamlined mixture of functional and decorative clothing - and wherever possible, to combine form and function so that the form IS the function, if that makes sense.
I also see them using a lot of natural organic shapes as inspiration for their clothing and architecture, so to me, the “Art-Nouveau-by-way-of-Norse/Celtic-design†that Weta Workshops seemed to be so fond of throughout the New Line franchise feels... well... just about right on the money! To me at least.
Particularly for the elves of Rivendell, Who dress elegantly, in long flowing tunics and robes that have the feel of both Medieval Europe, and sometimes also feudal Japan, with a very... um... swoopy? Quality? Lots of long skirting, fitted sleeves, etc. The clothing is practical (for people living in the Last Homely House, anyway), and not overly complex, but finely decorated nonetheless (not gaudy, just very very fine). Vinework, scrollwork, pointed sleeves, etc. are all omnipresent, as are lots of meticulous small buttons, piped standing collars, and so forth.
Then you’ve got the silvan elves, who are even MORE naturalistic in their design, and to me, once again, it’s a merging of form and function. In my head that means fewer silks, more linens and wools - but still more fitting than would be seen in mannish garments, and lots of leaf-shaped sleeves and skirts. Lothlorien being a bit more high-class might take slightly more to the styles of the other high elves, particularly in Caras Galadhon, but the elves of Mirkwood, being of a somewhat less noble variety might have had a more “mannish†look to their garments. Or then again, they may also have been a little more feral and naturalistic, taking even MORE cues from nature, until some of their clothing had, perhaps, almost the look of being grown more than sewn.
Personally, I also quite like the overall look of Legolas from the LotR movies, in that he’s really wearing a surprisingly simple outfit. He’s got Soft shoes with gaiters that function basically as boots, then simple hose/leggings, a silken tunic (I’d have probably chosen linen or wool for traveling, but he IS a prince, after all), some bracers of the same supple leather as his “boots†(of which really only one was probably needed for archery, but a pair is fashionable after all
), and finally a tunic of durable suede leather, with leaf-shaped seams and hems, as well as some very tasteful embellishment in the form of Subtle silver vinework traced across the chest.
Overall, it was rugged and practical in its way, but also elegant in cut and finely embellished - in a word, elven!