The key to being prolific is focus. Well, obviously. Of course if you focus you can do a whole lot more of that one thing. For me, at least, it wasn't quite that simple. I had to really become aware of just how limited my progress would be if I didn't focus more, and also be a little more tolerant of that. See, I used to try to do a number of different things pretty much every day, in at least a bit of depth. It was cool. I learned a ton every day (when I was able to maintain the habit), but I also wasn't able to keep it up consistently. Which lead to fear.
The fear is the killer. You can't be afraid of just getting started at all, or else you clearly won't be able to make much progress. So, realizing that while I could be quite well rounded if I kept up my course of action, but never really contribute anything great, I decided to look through my habits and figure out what to shitcan. I went from around ten to five habits I was committing to doing every day. This was scary in a different way, because I thought, well, if I don't have habits for these five things I'm dropping anymore, will I actually still do them? So far, it seems the answer is yes. I do more of the five habits I kept, but I actually still do just about as much of the five habits I didn't drop, or rather just a little bit less. The difference is that I'm doing so much more of the five habits I kept.
Clearly, since they are the five I kept, they're the more important ones. They're the ones I'm doing more of now, with more consistency. This is clearly the most win win a tradeoff like this can get. I don't feel like I've lost out on the five I dropped, but I do feel like I've gained significantly on the five I kept, and for that, I'm super glad I did this.
While I'm on the topic I'd like to point out what I think most important about being prolific. A lot of people (generally ones who haven't done so much creation) have the idea that great work is the result of genius or great talent. I think it's actually a lot more mundane than that. Everyone produces work that varies from a lower to a higher level of quality. If you do a lot of work, then you can choose to share your good work, and not burden the world with paying attention to what sucks. What's more, the whole range of quality you produce will actually shift upwards over time, as you realize (perhaps not consciously) what habits or techniques lead to higher quality work, you'll do better work overall. And you'll still be able to only share the good work. Or share it all, in some settings that doesn't matter. Like for coding, I just put everything on github, totally indiscriminately. For writing, I'm a fair bit more selective.
The key, once you've achieved prolificness, to maximizing the utility of it, is to pay attention to the possible payoffs of different kinds of work. For writing, there's potential negative payoff writing bad shit of whatever sort. You can offend people, or lose followers that you might not have lost if you'd more carefully made the point (that distinction is key: it's only losing them for the wrong reason that's bad, not losing them in general). For publishing code, though, there's no downside, basically, so I publish basically everything I write. No, really. I even published a script I wrote to warm up my laptop by running infinite loops on each core.
P.S.: A related piece that I really loved last I read it was Hamming's "You and Your Research." I'm not going to link to it, because copies die and new ones come around, but if you google it you'll be able to find it for sure.