Like any lawyer who has been out of law school awhile, I've been involved in hiring, managing, and mentoring many younger lawyers. What skills do I consider most important when hiring a new associate for a litigation practice?
Deposition and trial skills are always highly valued. Since a lawyer often can't control the type of experience he received at a former firm, however, a young lawyer can be forgiven if he still needs training in these two areas. But a young lawyer can't be forgiven for deficiencies in two other important areas: how to write and how to work up a case. Both of these skills can be self-taught with the basics provided by a legal education.
Since many young lawyers don't bother to teach themselves, it's an easy way to set yourself apart: work on your writing skills, and learn how to take a file and do what is necessary to get it ready for trial. Neither set of skills is dependent on mentors: although mentors help, you can learn both by reading books.