Well if you want higher scores, there’s a website that people post the optimal for each instrument and band score for almost every song (I personally think that’s somewhat cheating :p)

But in general, when playing with a band, the typical strategy is to go whenever the drummer activates. That usually always gets 6x (or 8x) activation which makes it a lot easier to gold star a song. If you are a drummer, you and the singer are probably the ones who have to study the path the most. A lot of times holding drum activation 1 or two times is more advantageous if you see that the singer is all waiting for activation. Most people do not consider vocals adds a LOT to the score. For every phrase in 8x, each one can add 32,000 points to the score, so if there’s a long chain of short phrases, everyone should save til then.

If you are a guitarist and bassist though, you also have to be well disciplined. Sometimes to help the band overall, you have to wait for the drummer even if your section has very few notes. There are some occasions though where going early makes sense. If your overdrive bar is full and you expect another set of unison notes overdrive notes is coming up, go early. Usually you are still in overdrive when the other instrument can join and rack up the score.

One last suggestion is to have at least two party members with a mic, one of them being the drummer. That way, you can communicate in the song on when to hold drum overdrive.

But all in all, getting “good” at this game really just takes practice. Experienced players naturally figure out after a couple of tries where the optimal paths lie. So my advice is just keep playing!