Don't come across as arrogant. This is really hard because you do want to come across as confident. Players don't want to hear that you really have no idea what you're doing. I try to couch things in terms of intentions or goals rather than promises or certainties. I try not to take myself too seriously.

Show empathy. Chances are the players are engaging because your game is important to them. Their idea or suggestion may be ridiculous. It might ruin the game. That doesn't matter. You still need to put yourself in their shoes and understand *why* they are saying what they are saying. This can be as simple as acknowledging that the player is upset. Being upset is a totally valid way for them to feel! Players are often better at detecting problems than they are at suggesting solutions. Try and understand the problems they are trying to solve. But at the same time, don't dismiss or belittle their suggestions, even if they aren't feasible.

Build trust. This can take a long time and unfortunately can erode quickly. But if you have a reputation then players will often forgive the mistakes that you are almost invariably going to make.

Be authentic. This is a great way to build trust. Be as honest as you can. Don't leak information or throw colleagues under the bus, but otherwise try and be transparent about your reasoning. Admitting mistakes here can help a lot.

Don't get sucked into arguments. Yeah, I know: sometimes people on the internet are wrong. But it's not your job to win arguments. It's your job to communicate with players. If something has gone back and forth a couple of times, it may be time to move on.

Stick to higher ground. This one is tough, but the fact is you are in a position of power since you are the one working on the game. If you pick on a player, even if they made an abusive comment and totally deserve it, you are going to come across as a bully. If you insult someone who insulted you, it's only your comment that will get quoted across the internet.

Be transparent about the process. You don't want to convey that your opinion is set in stone, but you also don't want to suggest that it's up to player vote (unless it is). The way I try and describe it is that developers want to make informed decisions. The players provide the information, but the development team makes the final call.

Don't get addicted. This is a mistake I see a lot of developers make who are new to community interaction, and no doubt I did it myself on my first job. Having players hang on your every word can be exciting. Making someone happy by promising a change can be rewarding. Just be careful. It's easy to over-promise. It's easy to neglect your day-to-day responsibilities by trying to be too responsive to player engagement. Players would rather have you for a year than every hour for only a week.