Don't devote endless pages of your brief to the law of summary judgment. One or two paragraphs is enough.
Don't string cite.
If you cite a case in your brief, no matter for what point, be prepared to be able to discuss it.
Understand and apply the rules of burden of proof as it pertains to your appeal. If your opponent has the burden of proof, remind the bench of that fact and, of course, tell them why the burden has not been met. Conversely, if you have the burden of proof, don't be afraid to alert the bench and advise them of all the cogent factual reasons you have met that burden and the fact that your opponent hasn't controverted it.
The ability to field questions during oral argument is a vitally important skill for an appellate advocate. Here are some points that come to mind:
a) Never cut off the questioning judge, as tempted as you might be to jump in with an answer. Take a deep breath and let the judge finish.
b) Welcome questions from the bench. Questions mean the judges are awake, alive and involved. As an appellant, if you face a silent bench, you have probably lost.
c) If you can't answer a question because, for example, it pertains to information in the record that you can't locate just then, or if you just don't know the answer, don't spend precious time leafing through the record or worse yet, guessing on an answer. Instead, suggest that after argument you will search the record and provide a written response. Keep your argument moving forward.
If a particular judge evidences hostility to your position and, worse yet, takes up an inordinate amount of time, when the red light goes on, don't be afraid to ask the Justice Presiding for a few more minutes to articulate your position. Try: "Your Honor, as you can see, I have utilized a good amount of my time in an interesting exchange with Judge X concerning questions she raised. I would appreciate it if you would allot me a few more minutes so that I can complete some thoughts I didn't have an opportunity to raise." I can't say this will always be effective, but a JP sensing you may have been roughed up a bit may be receptive.
And, let's say you are representing a criminal defendant on appeal and a member of the panel says: "And, counselor, isn't the error you rely on unpreserved?" Obviously not a friendly question and frankly one that could be called "unfriendly." But there is even an answer to that: "Absolutely, unpreserved, Your Honor. But, if you will hear me out, I think you will see that this is a case that cries out for the court to utilize its interest of justice jurisdiction."