Last Halloween my son told me it would be the last time he went trick or treating. He was 12 at the time and I thought he was appropriately giving the Halloween tradition up. However, he wanted a costume that was the best elvish costume ever! That meant I had to do armor! There are some great websites that use materials other than metal to make elvish armor. The websites below are wonderful resources for making armor and other costume elements for elves.
Haldir's Elven Archers
Craft foam tutorial
These sites have templates for armor which I used for my son's costume. They have pictures of the actual costumes from the movies as well. These are very detailed sites. I actually used the craft foam tutorial to do my son's armor. It was a lot of work but looked amazing. I spent the majority of my time covering the craft foam with a glue mixture so it would look shiny like metal. I made the elvish writing on the hip armor by using a metallic fabric paint to create the raised areas.
This was an exciting project for me because I am such a LOTR fan. I will say that sewing velcro onto spandex material is horrible! I only completed that task with a lot of colorful metaphors! The armor on the arms was done in this way because I did not have time to make some kind of gadget to attach the armor to his arm any other way.
I also made Haldir's pin that can be seen on his cloak in The Two Towers. I also made this out of craft foam.
The other clothing was researched using the above sites. I tried to make all closures authentic to the time period so no zippers, or buttons for that matter, were used. I mostly just used laces to close the garments.