If you use a laptop regularly — and especially if like me you’re tall and have a long torso — then I can’t recommend the Nexstand K2 laptop stand enough.
It’s spared my back many times over. I’ve been using mine for years. It’s compact, durable, lightweight, and easy to use. I use it with a 16" laptop that weighs ~2 kg.
(I stole the photos from their website because I’m lazy, but I really do have one that I’m using right now and have been for years.)
(I don’t recommend the K7 model. I’ve tried it and it’s inferior.)
(You can find the K2 brand new on eBay pretty easily.)
(In fact I just bought a couple via eBay, just to have a few of them “in stock” à la @siracusa )