A great writer is like the host of a great party. The host is primarily concerned that the guests are enjoying themselves and getting good things out of the experience.
A host avoids indulging him- or herself because a host's obligation lies elsewhere. By the way, that's not a bad thing. Attending a party yields one kind of enjoyment. Overseeing the party yields another.
When you write something, think of yourself as the host. It's not about you. It's about your guests.
(This splendid idea comes from Charles P. Curtis, Jr., a brilliant writer and thinker of the mid-20th century.)