Conduct settlement conferences. Assist the judge during trials. Write jury instructions. Write draft opinions and orders. Working at the appellate level is normally thought to be more academic and reflective.
More time is spent on each case and there is no contact with attorneys.
The duties and responsibilities assigned to them allows them to learn more about how courts decide cases than an attorney could ever hope to learn in private or public interest or government practice. Clerks fine-tune their writing skills and learn exactly what makes a good brief and argument. They learn to omit information the court does not want to hear. For clerks that are not certain of the type of law they would eventually like to practice, the experience gained while clerking often points them in the direction of their future law practice. Upon completion of clerking for a trial level judge, clerks normally find that they are much more marketable.