Yom Kippur is the most important day of the Jewish year. They day in which we confess to God our mistakes and misdeeds and we resolve to improve our actions during the next year. Hoping that HaShem will accept our apologies, inscribe us and seal us in the book of life. Now, as important as Yom Kippur is, if we fail to do our homework previous to Kippur, the most important day of the year might become the biggest wasted opportunity of the year. BEFORE Yom Kippur begins we must ask forgiveness from those whom we might have offended or caused any damage, emotional or material. During Yom Kippur the transgressions between us and God (Shabbat, Kashrut, Tefilin, etc.) are effectively forgiven by confessing them and resolving to improve. But we are definitely not forgiven by God for those offenses made toward another human being: bullying, cheating, lying, stealing, embarrassing, talking badly about someone (leshon hara'), etc. All these transgressions are NOT forgiven in Yom Kippur unless we first appease the victims and ask for their forgiveness.
If we are serious about this, we should sit with ourselves for a few minutes with pen, paper and a humble heart. We should review in our memories the times in which we might have caused pain and damage to other people: friends, colleagues or family members, parents, spouse, etc.
Then, we should think what would be the most effective way of appeasing each particular individual. By phone or in person? By a long email or by a text? Describing exactly what we have done or being more general? Since every person is different and every case is unique, there is not one formula to appease every individual. We must use our common sense and find a way for our apology to be sincere, credible and effective.
Asking forgiveness is probably one of the most challenging tasks we might need to do in our lives. Because we need to admit and say: "I WAS WRONG". It takes a lot of humility and emotional strength to face the victim. I think it helps if one considers the humiliation as part of the Kappara (atonement) within the Teshuba process.
A second list we should write ASAP is a list of our debts. Money we owe in our business or to providers; to friends or family members; unpaid community donations; Tzedaqa that we have promised to give, etc. We should prioritize those debts that have expired or about to expire. This is the right time to do it. Today or (literally) during the next couple of days.