Hi i have corrected your question. First of all, if we want to succeed in a given task we have to include two major elements:
1- The choice of the work: It is very important to choose suitable work, one that we like and for which we possess the ability to do well.
2- To plan objectives: We must plan our activities, have clear objectives and to check from time to time whether we have reached what we to do planned at the beginning.
My answer is that as a teacher, planning is crucial, because without it my classes wouldn't learn anything. As for the work, I have to teach a set syllabus that builds on skills learnt previously and I have to prepare my students for the next year.