How to Spot Fake Nintendo DS Games

How can I identify counterfeit Pokémon?

Hey, I used to collect Pokemon cards (1-3 years ago, I was only 14), now, also because of the hype, but I had planned for a long time, I want to start collecting Pokemon cards again.

I looked through my old collection again and found 3 obvious fake cards (but they weren't good cards either). I don't think my other cards are fakes or at least it's not clearly fake.

Now I would be interested in whether there is a 100% feature that exposes fakes.

Of course there are many features that suggest it e.g. that the "Tm" on the back is not there or the "bright spot" but with some fake cards on the Internet (fake cards from videos for demonstration) this "Tm" was still there and it was also with my obvious fake card ("Tm") not there) this "bright spot" did not work.

There are also clearer features like that the holostructure is somehow different, but that's rather difficult for me to recognize for semi-poke professionals.

So now my question: What are the characteristics of cards and purchases that indicate fakes?

Thank you in advance for your answers ^^