Some tasks require a particular computing context (necessary apps all loaded, and distracting apps all closed), and I prefer a discipline of doing them only for N minutes (N=50, for example) at a time before quickly writing up the status quo and the next step, and moving on to something else.

(In my case, tasks like drafting text, writing code, sketching or refining diagrams etc. )

I have an OF context for each of these working environments, and a script which uses the Concentrate application to reset the computing environment, and also set a timer, based on the OF context and estimated minutes.