The first thing I would say to young writers is, "Don't do it, unless you can't stand not to do it. " And the second thing I would say is, "If you do do it, and get into it, the constant rule you should have in mind is to explore your material. " It sounds simple, but it isn't, because people often want to get from A to B, and they don't stop to look at what is in the material.
If one is but secure at the foundation, he will not be pained by departure from minor details or affairs that are contrary to expectation. But in the end, the details of a matter are important. The right and wrong of one's way of doing things are found in trivial matters.