I am not any kind of spiritual guru, but I will try to share some thoughts.
1. Negative influences
I simply try to avoid watching shows that I think would be a negative influence on me.
As a positive example, I'm currently watching the original Patlabor TV show, which is not only clean but at times downright edifying.
In my case, if I pay attention, I can usually tell if something is having a negative influence on me by paying attention to my state of mind. If you feel like your state of mind is becoming darker, or you are behaving towards something in an addictive way, then those could be warning signs.
2. Avoiding idolatry
Including this question, a lot of times we talk about the way we are supposed to live in a negative way: don't do this, don't do that. Don't fall into the sin of idolatry.
But, the virtues are not just about not doing certain things, they are positive values. For example, in the case of greed, the positive value would be generosity, and in the case of idolatry (loving something else more than God), the positive value would be loving God more than anything else.
This is a teaching that I think came from a pastor named Fr. Roman Braga (iirc who it was that said this), but a helpful way of thinking about this is that you can try to pursue holiness by focusing on and trying to fight against all the negative things you see in yourself, whether it is greed or lust or idolatry or something else. But a far better and simpler way of doing it is to "turn on the lights" by cultivating your love for the Lord and filling your heart with that. Then the light drives away the darkness.
So instead of the issue being, "How do I NOT love an anime show more than the Lord," it's, "How do I love the Lord more [than these anime shows]?" In any human relationship, spending time with someone, or thinking about them, gazing on their picture, and so on, is what strengthens a person's feelings for another person (hence the story about a woman whose beau wrote her a letter every day, and she ended up marrying the postman). We really do tend to like people more when we spend more time with them. So, to love the Lord more, it's helpful to spend more time on your relationship with him. It could be listening to spiritual music or spiritual talks, reading the Bible (especially the Gospels) or spiritual books, spending time in prayer, both at home and in the Church, looking at pictures that remind you of what the Lord did for you . . . whatever it is that is inspiring and inflames your love for the Lord.