"Giving one some skin" is an informal way to describe the act of high-fiving or shaking hands with someone. There are plenty of other synonyms that can be used instead of this phrase, such as "slapping palms," "fist-bumping," or simply "shaking hands." Each of these synonyms can be used in different contexts, such as a casual greeting among friends or a more formal handshake in a professional setting. No matter which phrase you choose, the act of giving someone some skin is always a positive and friendly gesture that demonstrates your appreciation and acknowledgement for the other person.