When I made my Claire cosplay from Darkside Chronicles I used the same reference picture that starnes82 linked, and a smiliar one to this for her design on the back of the vest.
http://www.google.com/imgres?q=claire+redfield+let+me+live+png&um=1&hl=e n&sa=X&biw=1280&bih=582&tbm=isch&tbnid=NeyaxAeTfuP XWM:&imgrefurl=http://cosplaynewb.com/&docid=j9CLqI9zzzNFOM&imgurl=http://fc00.deviantart.net/fs71/f/2010/190/c/f/Let_Me_Live_ID_by_RedfieldClaire.jpg&w=800&h=821&e i=at9dUNixKce62gWd8oDICg&zoom=1&iact=hc&vpx=225&vp y=126&dur=7607&hovh=227&hovw=222&tx=126&ty=131&sig =106476631208678170701&page=1&tbnh=121&tbnw=123&st art=0&ndsp=27&ved=1t:429,r:1,s:0,i:73
As for materials I made mine out of Vinyl, hand painted the design on the vest using acrylic paint, and used acrylic sealer when finished.
For her belt buckle I ordered a plain silver oval buckle and painted the brass knuckle design on it with that "glitter 3d paint" people use on t shirts and such, then painted over it to match the buckle.
In the reference picture that starnes82 provided it shows Claire's choker to be blue striped and its not in game, its just black. (I think the creator of that ref image enhanced it to their liking)
Also in game her belt is not that light of brown its much darker, and her ponytail tie is red not black.
Hope all that helps, if you have any questions just lemmie know. =3