I'm playing a Bosmer this time through, and I always RP my characters to the best of my ability as provided by lore. But I'm having a hard time fleshing out some aspects of this character to make him "special" among my other characters without breaking what lore exists on the subject.
What I've determined so far:
1) Best archers in Tamriel
2) Best animal hunters in Tamriel
3) Masters of the forest (but then again, so are the Khajiit for some reason according to A Dance in Fire, despite living in a rocky desert)
3) Similar stealth skills as Khajiit and Dunmer and similar speedy acrobatics as the Khajiit, although I'm uncertain how this benefits them outside of the ultra-dense forests of Valenwood; would they not be "fish out of water" in an open environment like Skyrim?
4) Much "jollier" and light-hearted than the Altmer or Dunmer and much less obviously "sly" than the Khajiit, always giggling in the face of danger, showing deference to authority (no matter the race), and rarely showing any sign of overt hostility, but masters of passive aggresivity. An unnamed Nord in A Dance in Fire, Book IV states: "They're congenital thieves, even worse than the Khajiiti because they are so blessed meek in their aggression".
5) Considered to be the two most "untrustworthy" races in terms of thievery in Tamriel (what, no Dunmer?). The Speech skill book The Buying Game states: "I don't know any shopkeepers anywhere, no matter their open-mindedness, who aren't alerted when a Khajiit or a Bosmer enters their shop. Even Khajiiti and Bosmeri shopkeepers."