Depends. Usually I do plan a lot and I am into details and predicting situations from every angle getting prepared at the same time for almost anything. However not all of the time things work flawlessly so sometimes I do have to flow with what come out. I admit that I don't like going with the flow, but I also acknowledge the importance of sometimes going with the flow and letting spontaneity to solve what it comes and climb mountains. This way a lot of useless stress can be avoided. However, I think that the best recipe would be to mix both of them. Plan carefully and let the flow of events bring you the solutions for unexpected bumps on the road.