In addition to my previous post on being inspired by fashion/costume history, I've found one more great archive (dangerous for Mondays) of iconic fashion pieces - an archive of V&A collections. The best thing is that every item has a very detailed summary for those interested in labels, dates, materials, practical and historic side of things. Honestly, this is dangerous for costume addicts, don't enter the page at work or if you are procrastinating on something.

V&A Collections