Christian Hell: how does one avoid it?

If you believe in the Christian Hell, please feel free to summarize your best understanding, in your own words, of what a human being has to do to avoid the infinite torture that you think they deserve.

Heaven signed to the right, above, Hell signed to the left, below.
Help! Which way to do I go?

Is one saved by good deeds? Kind acts? Tithing? Proselytizing? Faith alone? Genuine repentance? If genuine repentance is a key… what things must you repent of? If your answer to that is “sin” then please explain what sin is. If I gave you a hypothetical moral situation, would you be able to say whether a given action by a given character was or was not a sin?