Be religious about writing down what you're doing, make a habit of referring to this list when you find that you're bouncing around from task to task.

Sometimes I'll hit HN if I'm waiting for something to finish, and if I was in the middle of something complex I've needed to write down what I was doing, even if it was only for literally a minute.

Also, when incrementally learning something it can help. Writing down in your own words how something works can help you if you only have small chunks of time to learn something.

Thanks for this, I'll try it.

I found writing down things I learned (or typing them in) makes them more likely to stick in my mind. Particularly small phrases that pop out.