Know what you are going to say, before you say it.
Let's face it, referees take a lot of crap, but there are times that we are asked genuine questions too, ones that we should answer. Not the "how can that be a foul?", questions, but more the "direct or indirect?", "who was offside?", or "how much time is left?" questions.
My thought here dear refereeing friends, is answer very carefully as anything you say CAN and WILL be used against use in the court of public opinion, and even in a report to the league or federation. It is critical that you communicate with players and answer their questions at times when genuine. Here are a couple of specific thoughts:
First, if you are asked about your opinion, "what was that?", don't paint yourself into a box. "An direct/indirect kick" should be sufficient in most cases. If not, couch the answer as an opinion, "I though they handled the ball." Nothing fancy, no long discussion. Quick answer and move on as quick as you can.
Second, downtime can be trouble. Keep the match moving as best you can to limit running conversations. Less is more in this regard. If there is an injury, attend to the player and focus on them, not the conversation.
Third, don't let a conversation get away from you. If you decide to engage a player in conversation, make sure it does not devolve into a shouting match. Keep it brief, and keep it positive.
Fourth, know the LOTG cold. A referee stands to really embarrass themselves and damage their credibility if they are discovered not understanding the LOTG. A better play is to avoid the whole discussion if possible.
Lastly, don't be afraid to talk about non-soccer stuff before, during, and after!! Many times I would talk about pitch condition, weather, stadium, family, kids ... whatever, with players. This is great as it builds the bonds that are the underpinning of high level match control.
In all cases, think about your responses before they leave your mouth. You can't take them back, and they can be very damaging to you, and others. Just ask Mr. Amendola.