Here are a few tips from the new Cross-Examination Handbook, which I posted about in March: Seven Essential Impeachment Cross Techniques--
- Assess and adjust. What type of witness are you dealing with? Basically honest? Prone to exaggeration? A liar? Know your case and the witness well enough to be able to adjust your cross-examination approach on the fly.
- Lock the witness into testimony. If you don't pin down witnesses to their inaccurate versions of the facts, they're apt to wriggle free later.
- Establish a motive. If you are trying to make the witness out to be a liar, you'll be more successful if you establish the witness has a motive for lying.
- Paint a picture for the jury. Establish your points fact by fact, allowing the jurors to reach the one obvious conclusion on their own.
- Close the exits. After locking witnesses into their own incorrect version of the facts, you also have to bar the escape routes. Try to imagine how you would do it if you were the witness.
- Surprise. Don't allow witnesses to know the precise objective of your impeachment until their testimony is locked down and the escape routes are closed.
- Visuals and other tangible things. If you can add visual aids to your impeachment, do so, as it makes you more persuasive and aids the jury in remembering.
Source: Cross Examination Handbook, by Ronald H. Clark, George R. Dekle, Sr., and William S. Bailey. The seven points are from the text; the shortened summaries of each point are my own.