For too many people, the word ritual conjures up either a repetitious rite drained of all meaning, or a dark, hugger-mugger meeting of individuals up to no good.
However, for our purposes, a ritual is an action repeated over time or at specific intervals, the purpose of which is to provoke change in the participants.
That change might be a transition in a state of “work-mind,” or it might be to refocus your energies in a particular direction, to name just two examples.
Another word for ritual might be structure.
What kinds of ritual are we talking about? Setting up a particular place to do your work. Reserving a time of day to do your work. Using a favorite pencil. Putting on a particular playlist as background.
In Mihaly Csikszentmihalyi's highly influential Flow, he discusses "optimal experience," and how we humans can get ourselves into that mental state that allows us to produce new work without (too much) struggle. Ritual structure is one way to approach flow.
You can read blog posts about RITUAL here.