ATLA's website offers this advice: "Don't Be a Slave to Your Cross-Examination Script," by Jerome F. O'Neill.
Everyone who conducts cross-examination has a script . . . . Whatever that outline is, never follow it slavishly. There is nothing better than seeing your adversary cross-examine your witness and not listen to the answer, thereby missing a critical fact which they could exploit further during the cross-examination.
Ask the question and continue to look at the witness until the answer is complete . . . . This information is too precious to save a second or two by looking down to ask the next question. Besides, if you listen to the answer in the broadest sense of that term, you will find that your planned next question may be different than your outline suggests. It also may well be much more effective than the question you planned in advance.