As someone who's been constantly on the computer since I was 12 (30 now), I learned early on that it's good to know when I'm spinning in circles blindly more than progressing, and to then move away from it to a quiet place (maybe I'll pace around the living room, or work at the kitchen table), then work in "low tech silence."
As a programmer/designer, there tends to be a lot of conceptual thinking and synthesis involved with what I'm doing, which can often be done (better, even) away from the computer. When I'm on the computer, I'm either learning, doing/implementing, or screwing around. Deep thinking happens (better) elsewhere.
I wouldn't universally recommend typing on your phone, but I'm (relatively) fast at it, and I can do it wherever. The limiting factor is formulating and such anyway, for me.
My current view: https://m.imgur.com/cMXoY7H
Ideas come from anywhere.
Also, gardening/diy work that's not overly complex can let your mind wander a bit. I find it works both ways - I think about solutions to diy/garden problems while at my desk and software problems with a shovel/hammer/etc in my hands.
I also have a sketch pad where I can work out ideas on paper.