Note that vocal range enhancer gives +1 to social skills. Cosmetic 'ware can give you the situational bonus for being attractive to the target (and actually increase Charisma, if you use the optional rule). Mentor spirits such as Dragonslayer and Moon Maiden can give social skill bonuses. Some qualities give situational bonuses, such as first impression or fame.
Social skills are actually fairly easy to boost, because there are so many dice pool modifiers available for them. Be careful, though, because a lot of those modifiers are situational (fame or first impression), have drawbacks (enhanced pheromone receptors can give penalties in crowds or areas with strong smells, glamour makes you very distinctive), or are commonly considered cheesy (most GMs house rule or outright ban emotitoys and empathy software).
Social skills, unlike combat skills, are an area where I would recommend taking a skill group - both because the Influence skill group is one of the ones with four skills, and because all of those skills are useful.
