I feel that I am much more efficient when I'm focussing on one thing. I'm going to try doing that more. Of course, I don't want everything to fall to pieces, so perhaps if I surround my main line of focus with little blips of side stuff.
Right now I'm focussing on a machine learning task for work, but I'm writing this blog post on the side. I'll go back and do more machine learning work, and when I need a break, I'll do some other small non-main-line task.