A nice person's self-image is based on pleasing and agreeing with others.

Instead of just agreeing and being nice, one should add unique value and perspective.

If you only agree with everyone, you may even not be that valuable to the team.

When a conflict-avoiding person has to disagree or has to add his perspective, he can use the word 'And' instead of showing disapproval of the team's options by saying 'But'.

Another strategy is to hypothetically imagine a different scenario with the team members, putting across your point as a brain exercise, not as a commandment. The team is then less likely to contradict you.

If you disagree with a decision and want to preserve your reputation as a nice person, you can ask indirectly, pointing towards the impact of the teams' decision, instead of making a direct statement criticizing or finding fault.

An open-ended question will help add value and invoke discussion.

When a proposed course of action is wrong according to you, try to understand the core issue, or reasons, that led to the decision, instead of complaining. This will help find common ground with others and take the discussion in the right direction.

Another 'nice conflict' tactic when you see an outrageous decision being approved, is to ask for help.

Asking for help to understand the decision indicates you are not endorsing it. You can then ask open-ended questions to steer the decision the right way.