How do you improve your writing output?

I haven't focused on writing output as much as I have on time spent writing. When my kids were younger, I traded babysitting with friends, and spent my child-free time focused on writing. Now that my kids are in school, I block out a part of the day to focus on writing. Some days I get a lot of words, others, I don't, because I'm more focused on finding the right word, or doing research, or doing a writing adjacent task. The important thing is I don't get distracted by social media or other things during that dedicated writing time.

As for finishing what I started, I have abandoned things, and I have finished others. I have to give a good faith effort to something. Try to at least finish a draft so I can look at it as a whole, and give at least some thought to the problems I encounter, whether in drafting or editing. If I find that I'm not coming up with a solution, and I'm not excited about it, then I'll put it down. I temper the temptation to run after a shiny new idea by writing down the main ideas so I don't forget them, and then planning when I will get to it.

That's fair, and you make a good point: solving a difficult problem with a story or doing research is progress with writing even if it doesn't come out in words written. sometimes that's more progress than writing a lot of crappy words that don't even come together in a finished piece.

I write and edit on my commute and often get more done in 20 minutes than I would in double that time at home. Queues or other waiting around can work too.

I make notes on my phone or with pen and paper. They might be a single sentence, dialogue or an idea for a scene or something else for a story. I have written a couple of stories on my phone when there was nothing else to write with available.

I started listening to podcasts earlier this year. Not just writing-based, but all sorts of topics. The BBC have loads of great podcasts that can spark ideas - many available on the World Service, so not just for UK residents. I'm enjoying 30 Animals That Made Us Smarter and Desert Island Discs a lot currently. Sometimes real-life human stories give me ideas for stories or how to approach a particular situation in one of my stories. Sometimes I hunt down certain topics for research purposes.

I'm a member of a writing group that meets up. We often write from a prompt or workshop on the night, sometimes having as little as 20 minutes to write before we share. I believe some of my best writing comes from that. The pressure* of that time limit forces me to write some of my best stuff, even in such a short time (obviously it needs honing after). I can't see why this wouldn't work online if people join at an agreed time. Perhaps using Skype and Discord or similar. *There's not really any pressure - it's a friendly group.

I often write from image prompts that include at least one person in the frame. That way, I already have a character and setting to start with.

I went to a workshop with a couple of editors from Smokelong Quarterly. Christopher Allen suggested the concept "one beautiful sentence," where you have many stories in a folder you're working on at once. Every so often, open a few up, add one sentence, and move on. It takes away the pressure of trying to finish one story. Sometimes you'll end up writing more than a sentence on one or more. I haven't got very far with this yet, but it's been a revelation so far. I'm not sure if the voice will be consistent in each story as I progress, but we'll see! I imagine it'll work better for flash and shorter stories.