Currently, the only way to define automatic run is by creating a timetable schedule. So, you need to define a time and date for the run. It happened to us that we have many flows running hourly. As they tend to accumulate info, the runs became much more time consuming. This only let us schedule the flows to run all at once.
We would need a functionality that allows flows to trigger other flows after correct completition. It would improve the flows to set a step by step process, and check their status beforehand. Furthermore, it would be great if by failure status we could be notified about the failures so we can review them.