This article is from the Stand-up Comedy FAQ, by Steven Rosenthal and Steve Silberberg (email@example.com) with numerous contributions by others.
A. There's no right or wrong answer. Some people feel studying others is a
must do, for some, it's a must don't.
Even those who feel that they really learn by studying others, have to be
vigilant about not copying them. Not the "I'm gonna rip that joke off"
copy, but the kind of thing where they recycle a joke or premise without
even realizing it.
For me, I'd rather fail with completely original thoughts and premises,
than be successful using bits and premises that were inadvertently lifted