It might be very tricky sometimes to find the right level of “musical intensity” on a cue. With inexperienced composers you sometimes get the feeling that the music is too distracting and active (e.g. on dialogue sequences) or too weak on more active scenes. Also, while the general musical emotion of a scene seems to fit it is often done either way overblown or too understated.
Think about how much intensity the music needs on a cue before you start writing the music. This of course needs a bit of experience and requires you to be able to have a certain distance to your music to perceive it as a whole with the rest of the movie when watching it in context. Just because a scene is sad doesn’t mean that it needs to be scored with all musical desperation you can put into it.
Generally, dialogue scenes and anything that might drift off into overly sentimental feelings are most sensitive regarding overscoring, so make sure to get them on the right level.