How to teach Smeargle Spore and False Swipe in every game?

Question

There are a lot of people (myself included) who ask questions like "How to teach Smeargle False Swipe and Spore in {Insert game here}"

I would like guide on how to teach Smeargle those moves in any Pokémon game where it's possible to do so, because I don't want to have to dig around in old questions just to find that someone hasn't yet asked the question for the game I'm playing. I think it would be helpful if there was just one question that you could go to to find out how to make a Pokémon catcher Smeargle in any game. (Maybe I should change the title to that.)

I know that there are other moves that are important, like Soak, Gastro Acid, or Odor Sleuth, so you can hit Ghost types and Magic Bounce/Good as Gold, but I'm fine with just the most important two, False Swipe and Spore. If you want to add the others, extra credit I guess.

Thank you to anyone who actually answers this.

Comments

In the Generation V games, you can receive an event Smeargle via DNS Exploit that has Spore, False Swipe, Mean Look, and Odor Sleuth. This is probably the easiest way to do this in Gen V.
https://bulbapedia.bulbagarden.net/wiki/List_of_local_English_event_Pok%C3%A9mon_distributions_in_Generation_V#2013_World_Championships_Smeargle

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In any generation since gen 3, double battles.

Or for any wild smeargle you can use false swipe if you're faster, it will never KO, and the Smeargle will Sketch it. For Spore, if you're faster you can continue to spam it on a wild Smeargle while it's asleep, then it will wake up after a failed Spore and Sketch it.

Let me know if you want me to explain that better

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Now all I need is for someone to put all this in an answer and check for any exceptions.