perspective and see how all the different parts of your project fit together into a larger whole. but on the other hand, you also need to be able to zoom in and get each of the details right.
notice that this rule does not specify the what ‘right’ level of attention to detail is. that will vary from project to project. so it is your job, as project manager, to determine this anew for each of your projects. but it is an important thing to get right, so give it careful thought.
what are your own project management rules?
please do tell us what rules you have discovered from your own project management 