It's helpful if you have a sense of purpose or Mission (the Elon Musk comment).
Using GTD, or something like it to manage your own task pipeline is really useful. Trying to figure out the exact next step wastes a lot of cycles. I've found that when I'm in that state, it's because I haven't broken down the task into small enough chunks.
Manage your energy (this has something to do with the tasks themselves, and a lot to do with what you eat, how you sleep, how you exercise, and your general mental state).
Offload, automate, or drop tasks that you don't actually need to do (yourself).
Remove distractions to make it easier to focus and control your attention. (I've been thinking a lot about this quote lately: What information consumes is rather obvious: it consumes the attention of its recipients. Hence a wealth of information creates a poverty of attention, and a need to allocate that attention efficiently among the overabundance of information sources that might consume it. -- Herbert Simon)