My answer to that changes quite often. But there are some that are consistent enough to warrant being here. The first is my writing. The second is Giant/Tiny, also known as G/T. The third is watching YouTube videos.
My original fiction is part of a giant multiverse. A variety of story universes can exist at once. I have an end in mind, but I don't yet know how I'll get there and what stories I want to tell between now and then. As for my fanfic, I upload them when I finish either an entire series or just the one story if it doesn't connect to others.
Here are the original fiction worlds I've uploaded so far:
Giant/Tiny, or G/T for short, is an interest I have. It revolves around significant difference in size, such as a human four inches tall or one fifty feet tall. The community for it has about a hundred people in it. I feel like I was late to discover it, only getting the idea to when I saw a particular video that reminded me of an anime movie that, at the time, I hadn't seen for many years. My curiosity led me to find lots of wholesome art involving it, and I got that movie for Christmas 2019 and saw it again, confirming that I had missed some details and misheard and/or misinterpreted others the last time I had seen it. I already knew that, though, because of the assistance of the Internet. Some of my writing, both original fiction and fanfic, also involves G/T.
This is my third hobby, and though I had done it when I should not have in 2014 and 2015, I really got into it in 2016 and onward. I follow a variety of creators, though I'm more active with some of them than others, and that isn't just because some of them don't post many videos. There are issues, though. For one, blocking ads is a must for security because not only do they cause horrible lag when the Internet connection is through Wi-Fi, but malicious ones mine cryptocurrencies, and while I don't know how those work, mining them with ads can't be good.