GM Tips & Tricks?

Hey everyone. I'm starting a new game in person with about 4 players. While it's not my first time, and I have looked at a ton of things online (from youtube videos to blogs to whatever I could get my hands on), I know one of the best tools is experience and play, along with having other GMs at your side. So I would like to ask all of you; What are some things to always have behind your GM screen? Tips on getting your players to get into character? Any major problems you've encountered and/or how to avoid them? What part of GMing do you love? What part do you hate? How do you personally handle problem players? I would love to open this up for conversation for not only myself and other GMs but for those who are interested in GMing for the first time! Thanks for your time :D ~Bunny

I'll post back with some actual suggestions when I'm not on my phone, but you probably want to delete this and post it in the specific uses forum instead of wasting your suggestion vote.

No need a friendly mod will be along to way there magic wand. 

From the Roll20 Community Code of Conduct : The Roll20 Forums exist to discuss topics directly related to the use of the Roll20 program . Anything that more fittingly could be discussed on another website SHOULD be discussed there. Here are some good places to discuss this topic: /r/rpg /r/gamemasters