The appellate practice is quite a different animal from a trial practice, but not many appreciate the differences.
The trial lawyer acts as both investigator and performer. Before trial, he must investigate the facts of his client's case. In civil litigation, he does this mainly through documents, depositions of witnesses, statements, and other pre-trial discovery. He must then create a compelling story with the facts discovered for the jury. With trial exhibits, confrontation of witnesses, skillful questioning, and an emotional connection, he leads the jury to a verdict.
The appellate lawyer deals in an altogether different environment. In his practice, the trial is over and the facts have already been established. His duty is to examine the facts in light of the law and persuade a judge or appellate court that the law is on his client's side. While there is an aspect of oral argument in appellate practice, the appellate lawyer's main tool is persuasion by the written word.
A good trial lawyer who understands the differences between the trial court and the appellate court will usually recommend that his client obtain appellate counsel rather than try to handle the appeal himself.