Programming

I like to just tackle little things using technologies I haven't used before. Write a small application in a new language to do something simple, and keep the project small in scale. You get the satisfaction of building something and of learning a new skill, with no pressure, and you get to know whether you like the language or framework. It doesn't matter if it doesn't do anything groundbreaking or clever, and doing this just keeps your wheels turning while carving out a little bit of creative computing space for yourself, not your employer.

Also consider open-source software you use daily (because that will motivate you) and check out their repos to see if you feel like starting to get involved.

Or bite off something completely different in tech, like robotics or electronic musical instruments.

And if you're just tired of tech, that's fine and you may just need a contrasting activity you can do at home. Then at least your work doesn't become your life.