Maintain cohesion by beginning sentences with old information
and moving to new. This tricky point can overrule some of the others. See the first example in point 28, for instance: "Some sentences, by placing a phrase or clause between a subject and its verb, break their momentum." Say you wanted to add the word "however" in
one of two places: at the beginning of the sentence or between the subject
and verb ("sentences" and "maintain"). Point 28 suggests the former
decision, which keeps the subject and verb together, but you might also
invoke point 29 and make the opposite choice. Similarly, the passive
voice and "to be" verbs can sometimes help you move from old information
to new; when two principles conflict, use your judgment.