With and without trailing slash in URL

Selected answers from the Dumb SEO Questions Facebook & G+ community.

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  Ammon Johns: Eventually, Google at least will work them out, mostly, and canonicalize them, but this is a bad practice, and very much a beginners mistake.
  
  Before the canonicalization tags were created, any web dev worth his salt would use 301 redirects to ensure that one and only one `true` version was ever used. Since canonical tagging was introduced, this is now such a simple thing that even sites without their own server can ensure just one version is used.
  
  I still recommend backing up canonicals with 301 redirects though, because the redirects help also ensure that users get the right address to bookmark, pass on, or link to, in the first place.
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  Nathan Nikolay Gaidy: Ammon Johns Thanks for explaining
  
  So if they are indexed twice I need not worry and Google will figure it out
  
  But how do I canonicalize example.com/page and example.com/page/ ?
  Just put the tag in the page code and that`s it that simple?
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  Ammon Johns: Nathan Nikolay Gaidy https://support.google.com/webmasters/answer/139066?hl=en
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  Nathan Nikolay Gaidy: Ammon Johns Thanks