I don't suggest taking "entertaining" as synonymous with "humorous." Non-fiction books, sad films, and football matches are all entertaining for some people. Entertain the HN audience by delivering the sort of thing they like - well considered insights and technical information.

Nor is the reference to timing implying comedic timing...except in a general sense of delivering your ideas when the audience is likely to be prepared in the right way to appreciate them. This fleshes out to when and where one comments - before HN became kinder, gentler, and larger, early snark on a rising thread was often worth a few points. Well considered comments on a recent popular thread will often do better than those delivered otherwise.

Timing requires understanding the audience or perhaps having a model of that portion you wish to reach. Writing for someone is a good first step toward being entertaining.