If you own a necklace, then I think you maybe have encountered this issue of getting it tangled or in a knot. At least I ran into this problem quite often before. I had to spend a lot of time to untangle it. So lucky, there is an easy way to untangle it and save time. 
In this video, The Crazy Russian Hacker explains step by step how to make sure this problem will never be an issue ever again.
Bonus Tip:
For tangle-free jewelry during your travels, unclasp the chain, thread it through a plastic drinking straw. For a shorter chain, cut the drinking straw to the desired length.
Via Real Simple
