The answer itself is "simple": musicality.
In practice, this is one of the most complex things to learn how to do as a musician.
What do I mean when I say to play with musicality? It means that there isn't some exact format or formula that you can follow that will specifically tell you to add a crash here or some toms here. It's all about context. What other instruments are in the band? What style do you play?
You can be inspired by videos of the greats... definitely! Use them to add to your vocabulary!
But you also need to start to listen to what the other instruments in your band are doing and compliment them in a way that enhances what they're playing, and simultaneously creates the emotional content in the song that you're looking for. It might change as you guys rehearse more often! And I'll throw out there that often, band mates are fearful of being drowned out by an overzealous drummer- so prove them wrong ☺
For example if you're on your way to an exciting bridge, you can continue playing the same basic beat with kick and snare but accentuate a great baseline by playing opposite beats (or concurrent beats!) with your crash cymbal. OR change up your "outro" (to those 8 beats) with some fun accentuations or patterns on your toms. There are also great drummers who repeat ad nauseam (because it's true) great drumming is also in the silence.
There really aren't any rules that say you need to keep the exact same patterns either, by the way, as long as the beat is consistent and you return to it. I think this really is the fear of the other musicians- they don't want to disappear, or lose their timing.
To reiterate,
- Listen to some of the greats
- Learn and adapt their vocabulary
- Listen to your band mates and what they're playing
- Use sounds that will enhance the emotional content of whatever is going on in the song at the time (exciting bridge? Crash! Toms pattern! More emotion? High hat!)
- Don't be afraid to use rests/silence to your advantage
- Think like a writer and use musicality to guide you.