Getting into a state of “flow” means being completely absorbed in an activity: focussed, in control, and creative. Read: productive. While we  have all experienced falling into a flow state at random and emerging, blinking, an hour later having blasted through a load of work, there are also ways of stimulating this state. Distractions are anathema to flow, so nix those first of all. Having specific rituals before beginning work can help, alongside ensuring you are invested in the work, and that the task is just challenging enough to stretch you without being too hard.

Source: learn.filtered.com