If I have one word of advice to any DM, it would be to play the game as a player as often as you can. There are a ton of reasons why I would make this suggestion and I’ll explain a few, but the first and foremost reason is you love this game. Being a DM is the only proof I need that you love this game and there’s nothing that will sour a relationship is feeling like you’re doing all the work and everyone else is getting to enjoy your work.
Playing the game will rejuvenate your DMing. Planning and preparing for a game is a lot of work at times. Even if you run a module or adventure path, there is work that needs to be done before the players ever show up. Getting on the other side of the screen will do you good.
You can learn new things from other DMs. DMing is an art as it is a science. The 5th edition of the game is especially geared towards this mindset. Yes, there are rules, but the main thing from the designers is that this edition is rulings over rules. Some DMs are more into the narrative and there are others who are way into the tactics of encounters. Depending upon your game, there are practices or tricks that you can pick up and use.
In the recent couple of months, I’ve luckily have gotten to play with two very good DMs, but two very different DMs. The experiences have very much impacted how I run my own games, both in tone and in ideas for how I want to handle some game situations. One of them is how to handle in 5th Edition the down time activities situation. While in my work game, we really haven’t had any down time as the characters have been on the move and doing things for the entire time of the campaign, I can foresee a time when that might change and they’ll want to do one of these activities.