I'm using Bona Traffic and Mega finish. Any good tips for touching up a miss or a scratch? How do you make the sheen the same without coating the whole floor?

try taping out the entire board(s), rub out the scatch with 150 or higher then coat the whole board(s). You shouldn't have a shine difference if you use the same finish. If the scratch went down into the wood, you may still see the indentation of the scratch, but at least the color will match. Good Luck!