So, I asked a dozen of my favorite professional artists how they manage art burn out. Here is some of the advice they dropped on me:
Don't commit the sin of working on shit that isn't interesting to you!
Divide art in manageable chucks with clear start and stop points: ideas, sketching, linework, rendering, etc.
Find your own rhythm and work with it, not against it
Make your environment conducive to art and free of distractions like phones and people
Have multiple projects to switch between when bored/not feeling it
Take time to be inspired; surround yourself with material!
Take pride in what you can achieve in your sessions and capitalize on energetic moments
Advance where you can: "20 min a day is better than zero min"
Block time chucks in shorter periods; quit for the day when it's quitting time
Use your time between chunks to review inspiring material!
Use the 'body doubling' technique and have art friends keep each other motivated (IRL, Chat, Discord)
If burn out comes, it will also leave. Art will return!
REST!