I think one of the most important things an official needs to possess is impeccable integrity.  There can be no questions about his/her impartiality. If there is, no one can be trusted and that is not good.

It is also especially important that you have good judgment. If someone has poor mechanics, but good judgment, we can typically fix the mechanics. But if someone has clean, crisp mechanics and mediocre judgment, it is hard to fix

It is also particularly important that you are consistent. Teams and coaches will appreciate it if you make calls that are consistent in the same situations/positions.

It is important that you remain humble and remember that people came to watch and/or paid money to watch the athletes and not you. You need to always leave your ego at home and not be adversarial. Instead, be approachable and willing to listen to a coach. Do not take it personally if he/her disagrees with your call. They have a vested interest in who wins and will do anything to give their wrestler an advantage. Let he/she voice their opinion and then decide if they have questioned your judgment and penalize them accordingly. If they were correct, fix the mistake and continue officiating. They are allowed (per rule) to have a discussion with you

You absolutely must have a mastery of the rule book and know how to apply it. There is no substitute for your knowledge of the rules.

This is important. You must look and act professionally from the time you enter a facility until you leave. The tone of your voice and how you communicate with coaches, the table, the event staff, and the police is critical in how they perceive you and your ability. Your body language it very telling, and it should be constant throughout the entire time you are in a venue. It is important to look confident but not overconfident. 

Find someone you trust and are willing to listen to…. preferably someone that is in a position that you want to be in. Ask them to watch you officiate and then actually accept their advice and/or criticism. 

It is important to continue to learn and evolve as wrestling evolves. You need to continue to watch wrestling at high levels to learn techniques and how to anticipate what wrestlers are going to do so that you can be in position to make decisions.