The toughest part is contriving a sustainable reason to interject yourself, but after that it's pretty easy. I say sustainable reason because some reasons, such as asking for directions, don't have much long term pull; they give you directions, and you leave!
Usually what I do is I listen in for a while and find a point where I can go, "Excuse me, but did you say X,Y,Z...?" which I suppose in FFXIV's more archaic language would probably look more like "Pardon the intrusion, but I couldn't help but overhear you mention X,Y,Z..." Anything that initiates a talking point and enables sharing, both from the group and from yourself, does the job well, . In caring about what they are already talking about, you gain an inroad that is still polite! (So even if you are well mannered, you can feel good about doing it, haha.)
Try it sometime. I've never regretted introducing my characters into RP I've seen in the open. The rewards are well worth the initial anxiety.
Usually what I do is I listen in for a while and find a point where I can go, "Excuse me, but did you say X,Y,Z...?" which I suppose in FFXIV's more archaic language would probably look more like "Pardon the intrusion, but I couldn't help but overhear you mention X,Y,Z..." Anything that initiates a talking point and enables sharing, both from the group and from yourself, does the job well, . In caring about what they are already talking about, you gain an inroad that is still polite! (So even if you are well mannered, you can feel good about doing it, haha.)
Try it sometime. I've never regretted introducing my characters into RP I've seen in the open. The rewards are well worth the initial anxiety.