Answer: Yom Kippur, with its confessional of "al chayt", takes care of our sins before G-d; there is even one very respected view in the Talmud (the view of Rabbi Yehuda HaNassi, no less) which maintains that Yom Kippur forgives even without the individual's repentance! (B.T Shevuot 13A).

Hence, the most important area for us to work on is that of our human relationships; gossip (even if its true), slander, taking advantage of those who are closest to us and whom we sometimes take for granted (like our spouses and even our children). The great sin of causeless hatred (even if you are sure there is a cause, and especially if you think the cause is leShem Shamayim), which leads to divisiveness and internal dissention is just the kind of societal worm that internally destroys the very infrastructure or our community and our nation.

Teshuva can sometimes be best be expressed by saying "good morning" and "good Shabbes" to everyone we meet. And recognizing the fact that the ability to overlook even what we may think is imperfection in someone else will only help us to better perfect ourselves.