Code review sessions really help. My office has started
these and we've all benefited. Just be sure that different
people offer up code each time.
You might also suggest informal office seminars on basic
topics like commonly used modules or specific perl
language features.
Lastly, if your employer has the budget, suggest sending
programmers to conferences and workshops as part of a
professional development program. Sitting through, for example,
MJD's Red Flags workshop can really open your eyes to your
poor coding habits.