As designers, we get to learn new things every day. Most of them are usually related to the way we discuss design with others, which tends to be a bit chaotic most of the times. Although I'm far from being an expert in these matters, I've come a long way since my fresh-out-of-college design years and I'd like to share some of the little things that we can do/say/think to communicate better with the rest of the team.
At Subvisual, designers are absolutely outnumbered in comparison with developers, which means we usually end up working on more than one project at the same time, at different stages. If this sounds familiar to you, then you know how messy it gets sometimes. One thing I have found to help smooth things out is to take a minute before asking anything, to give context about what it is I'm talking about. Same goes for when someone asks my opinion on anything.
It is as simple as a developer reaching me with "hey, on project X, when you get an invite for an event, do you think having 'Accept' and 'Edit' options on the Event Card is enough or should we add a 'Reschedule' option?"
And then, instead of a Yes/No answer I can explain the rationale behind that design decision and include him in it, saying something like "Well, we opted for having only those two because we assume there's a number of things a user would like to do with an event, but they could be grouped in 2 categories: Accept the event, or suggest changes. Those changes could mean a reschedule, changing who got invited or even changing the event's description. So I think we should stick with 'Accept' and 'Edit'. Does it make sense to you?"
If you can manage to instigate this sort of dialogue between your team, you're most likely to face less conflictual situations, because you're actually cueing your teammates into the design process, making it easier for them to understand your point and give you valuable insight themselves. Win-Win.