Next time you are in disagreement with someone, do not get tempted to move into a neutral zone. Simply say ’Sorry I don’t agree with you”.
If the situation allows, you should substantiate your disagreement with the reason as to why you say so, and what is probably you think is the right approach / choice.
If the situation doesn’t allow you to disagree in so many words – at the least you make it clear that you are not convinced with the choice made by the other person.
Think back to a time when you disagreed with someone, and were unable to express it at all. What difference do you find in how you felt then and now? Don’t you feel more empowered / confident / self-aware / authentic !