Setting up your workspace correctly is very important to make sure you don’t get into bad postural habits that might have long-standing consequences. We’re listing some advice below. But please remember that in all cases, the most important thing you can do is move.

Make sure to take frequent, moving breaks; take time to stretch and to move around. If you work by yourself, it’s easy to get too focused on what you’re doing and forget that you should be stopping for breaks.

There are many apps that can help you with that (e.g. Stand Up). But you can also team up with a friend/coworker to make sure to remind each other to take that break, or have joint coffees on Zoom while taking a walk.

If you have a home office and use an external monitor, keyboard, and mouse with your laptop, you can set up your workspace so that you limit the risk of repetitive strain injuries.

Ideally, a fixed work station should be set up so that:

  • Your screen or monitor is at eye-level, so your neck can stay in a neutral position throughout the day
  • Keyboard and mouse should be placed at a lower level, so your wrists can be angled down, and your hands can flow as effortlessly as possible on the keyboard.
  • Your chair should provide arm and lumbar support, and it should be adjusted so that you can keep your feet flat on the ground.
  • Working outside of a dedicated space is far more ergonomically challenging. Variable lighting can lead to glare and eye strain, chairs and other seating options may not adjust to your body size, and table heights are generally fixed. The best way to minimize stress to your body when you’re working on the go is to mix it up.

For example, you can set your laptop on a book or object to get the screen top to eye level for less stress to your neck. Then in 30-60 minutes lower the screen and get the keyboard in a better location.

And remember: the most important thing is always to stand up, take a few steps, and stretch! You don't need to do it all by yourself, either.

Check these apps - they can help eye and neck strain, support you starting a meditation practice, and of course remind you to move.
If you own a wearable device, chances are you can set it to remind you when it's time to take a break (the Apple Watch for example has a "stand" notification, which pings you to stand and stretch every hour).
Most injuries are reversible, so if you're experience pain or discomfort, seek advice. @pedro shared his experience on the matter:

Less than a year in into my first remote job, I started experiencing pain on my right wrist and accompanied by a tingling sensation in the palm of my hand. I had heard about CTS many years ago (Carpal Tunnel Syndrome), so I realized it had finally caught up with me. Fortunately, I came across some blog posts from people detailing how they overcame the problem without significant changes in habits or any surgery. The gist of it is that what was causing the condition was the habit of resting my palm on the table while using the mouse (and yes, I did use a mouse mat with gel wrist support). Fortunately, this was not definitive and could be reversed. Once I heeded the advice, got rid of the mouse mat and just started using the mouse without any support, the problem slowly went away.
The idea is that you keep your arm at a straight angle with your hand as you're using the mouse, eliminating the small weight you inflict on your carpal tunnel as you rest your wrist on a surface. One excellent book was pivotal in my change of habits after that: "The Healthy Programmer - Get Fit, Feel Better, and Keep Coding". It helped me get rid of pain due to bad posture by incentivizing me to do some simple but effective daily 10 minute exercises.