Like you said I think the secret is to build up a queue, at least that's what I've been doing, and I post like 2, maybe 3 pieces per week. But on actually producing more art I try to sketch every other day and then work a little more in the ones I like.

First of all, what works for productivity is unique for each person. Second, just because some people put out a lot of work does not mean that you have too as well. So don't feel like you are expected or obligated to upload more. In a large part speed simply comes with experience, but it also depends on technique and medium, personal style and just being a different person in general. You need to find your own pace. If you genuinely feel that you work slower than you could, that things take more time than you feel they should, then you can try to analyize your own workflow and technique to find out what are the elements you can improve on. But don't think that you need to be faster just because others are faster than you. That said, doing quick sketches and speedpaints where you give yourself a very short time limit and you are not allowed to continue once it's over, is a good way to practice getting faster. When you do that first, you will fail, you will keep running out of time without even getting halfway done, but you need to keep doing it over and over, for weeks and months and you will intuitively figure out ways to be more efficient. BUT... training for speed only really works if you have solid fundamentals to build upon, otherwise what you will end up with is formulas that you stumbled upon, that make things faster but you don't really know why and you are locked into the limitations of that formula. That is not true speed, it is a trap. Making a _good_ drawing/painting is always more important than doing it fast - unless you have a job where you need to crank out things within a very short deadline at all cost, eg. concept artists.

Part of it is that a lot of social media artists are doing it full time. Either they make all their income through things like commissions/freelance projects, social media promotion, online/convention sales, or they are supported by a spouse who pays the bills. Others have a part-time job not related to art but therefore still have a lot more time for art. Also, some of it will be multiple photos of the same piece throughout the whole process of creating it, shared on different days. Some of it is older work they're sharing or re-sharing. I've also known some artists doing webcomics or other work where they actually spend a lot of time "getting ahead" so to speak, where they have a backlog of work at the ready for social media posts as a buffer if they don't meet their posting schedule for their webcomic or social media, so that they still have something to post. Some will also save time by automating their social media posting process. There are ways you can schedule posts in advance to post automatically on certain days, so part of it may be good time management, in that maybe they spend one day a week doing things like planning out and scheduling social media posts so that an automated system will be doing all their posts for them throughout the week while they work on more art.

Some seem quick and good, but there is also a lot who seems to do variations of the same stuff over and over again and don't progress. I would not enjoy working like that, I will not let some algoritm dictate how I create art.

They are human like us, more often than not they sure a) repost b) old exclusive content from patreon c) they draw while streaming on Youtube or Twitch saving time and marketing their channel d) it's their full time job XD

Keep in mind that those artists spend several hours a day painting. They're not superhumanly fast (well, some may be), they're just skilled professionals. For example, think of the difference in speed and quality of your writing when you were 4 compared to your writing now. Speed sketching sessions helps a lot to improve speed. I'd sugest you try a tool like http://reference.sketchdaily.net/en and set the time per image a bit faster that what you would normally use. I've had the same questions as you, and with a lot of good practice I've been able to drastically improve my speed. At the moment, I'm more relaxed and I post when I feel like posting (although is a well known bad practice in social media).

I've recently taken up drawing first thing in the morning. For now I'm doing 30mins right after waking up and it 's a good way to make sure you draw at least a bit every day. I got the idea from Bobby Chiu's interview with John Park on YouTube.

Having a "process" can help alot. i've been working on creating and tweaking such processes to streaminline my projects further. my "illustration" process/check list will look different than my "concept design" one does. My concept design one will be missing the "color thumbnail" step for instance. Hope that helps.

I don't know if this would work for you, but for me, the way I made myself draw and paint more was by doing sketches of small simple things I love to draw and later when I feel like it one or two things that are relatively complex but I love to draw. Sometimes I love taking random ideas from people to change things up and make things fun! This also builds better visual libraries and a bigger skillset. Soon you will build this weird almost desire to draw a lot, but only if you don't force the process. Build your drive for it and good luck! ✨

Posting regularly on Instagram is challenging. I started a year ago with simple drawing nearly every day. The more I learned the more complex and time consuming the drawing became. Right now I post once or twice a week and I have to be very careful to not slip into a feeling of pressure while drawing. That is not healthy and the art gets worse (in my case). My solution for now is to develop different styles,one more simple and easy, fast- Another where I practice full illustrations (well 'full' within my limits). that really helped. In the end it is the question how you want to build your profile: Just your A game illustrations or also some practice drawing/sketches ect. Many big artists post steps of their process, sketches ect, to keep up the content.