One of the best pieces of advice to give someone who wants to improve their writing skills is to read widely. The idea is that you will be exposed to more and more writing in a wider variety of forms, including those outside of whatever genres you might choose to focus on, all of which is useful to you as a writer because it will give you more tools to use in your own creative work. After all, the various writing tricks authors use, their various stylistic quirks and so on, aren’t limited to a genre. If you see something cool and interesting in a science fiction story, you can figure out how to incorporate it into a fantasy story. Or if you find a particularly interesting way of phrasing an idea in a piece of nonfiction, you can find ways to do similar things in your own fictional works. The more you’re exposed to, the more you’ve learned and can incorporate consciously and unconsciously. Which is also true of running tabletop games (and storytelling as a whole, but you can pretty much extend any of this advice into any type of storytelling with enough abstract thinking, so I’m going to stay focused). The more games you play or run, the better you are. This is fairly self-evident to most people since that tends to fall under the “experience makes you better at things” bit of wisdom. I’d suggest taking it a step further, though, and suggest that you play a wide variety of games rather than just sticking to the ones your prefer.