Bring someone or something to mind, and say slowly: I'm sorry, please forgive me, thank you, I love you.
Say the four phrases silently to yourself, as a private practice, without expecting the other person to know.
Write plainly, in a sentence or two, what actually happened and what you wish had gone differently.
Before asking anything of the other person, name your own part in what went wrong, plainly and first.
Go to the actual person, in the tradition's original shape, and talk the problem through until it's genuinely settled.