So many that were mentioned above are also things I do. Walking is probably the best way to go about with anything really--it calms you down, gets your blood circulating, you get to breathe in fresh air, surround yourself in nature or at least pleasant scenery, and it just puts you in a nice, meditative-like state that allows your thoughts wander. I've had so many ideas just come to me that way.
A block might also mean you need a break, and distract yourself might be what you need (watching movies/shows, listening to music, cooking, cleaning, reading, drawing, etc).
I will often find myself rereading my own works, too, to get myself back in the mood and headspace of the story's atmosphere. Sometimes it's because a scene might seem too forced so I'll rework till it flows better.
If you've got friends with common writing interests (who are willing to listen), it's great to bounce off ideas with them and use them as a soundboard. It's a great way to sort out your thoughts with some supportive feedback, even without them contributing any input. I've had a few stories roughly planned out that way, too.
When it comes to drawing, watching a lot of amazing art tutorials on YT really reignites my inspiration and itch to draw, as well as reading comics by super talented artists. I also look back on old artworks, too.