I was unable to follow any site that featured a series of images showing the knot in various stages. The drawings were just too difficult to follow. At some point, I'd always lose track of what went where.
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Fortunately, there are some really good instructional YouTube videos.
I like the Southern drawl on the narrator's voice (especially at 0:29 when he says "cinch it down"). If you've got a wedding coming up, an easy way to practice without incurring suspicious laceration marks on your neck is to tie it on your thigh.
What about wearing a bow tie outside of formal wear? Personally,I think it's a tricky thing to pull off, especially if you're not a:
-professional nerd:
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-conservative pundit:
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-stripper
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Now, I suppose I'm being just a bit unfair. Interestingly enough, corporate culture seems to tolerate the bow tie, especially in the U.S. Every big American law firm seems to have one middle-aged partner in a corner office who wears bow ties as a matter of course. He usually has a collection of more bow ties than you can count, and is overall well-dressed. The bow tie is his thing (e.g., he's known as "the guy with the bow-tie").
In recent years, thanks to the rise of preppy-chic, the bow-tie has made a bit of a resurgence.
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As for me, I don't think i could pull off the bow tie in a casual setting. Because it's such an exceptional piece of clothing, it just feels a bit too affected for my liking (much in the same way as does wearing wool scarf indoors).
I did see a Dior(?) ad in men's magazines a few months ago, which featured a guy in black pants, white shirt and a black leather jacket, and a black bow tie. Unfortunately, I couldn't track down that image, but I did think it was a pretty cool look.