Okay here's a 15th level commoner.
Jack is a 40 year old farmer. His states are Str 14 Dex 12 Con 12 Int 14 Wis 14 Cha 14. He's lived through drought, orc invasions, locusts and livestock disease. Using his exceptional-but-not-heroic wits and muscles and lots of sacrifices to the gods Jack has prospered in a wild but fertile region were lesser men scrape to get by. He's what you might call "rural upper-middle class" since he's somewhat wealthy but most of that wealth is in the form of cattle, sheep, land and other such things. He and his large family live in a comfortable stone house with several hired hands who work for room, board and a few silvers a month.
His 7 feats are 1. skill focus (profession-farmer), 2. skill focus (diplomacy), 3. weapon focus: light crossbow, 4. toughness, 5. endurance, 6. skill focus (handle animal), 7. Leadership. The skill focus feats help Jack in obvious ways - with farm stuff or with negotions with merchants, the local gentry, etc... The weapon-focus light crossbow helps with wild dogs and kobolds that get too close to the farm. Toughness and endurance come from a life-tme behind a plow and sun-up to sun-down work. Leadership reflects the fact that Jack's natural charm and reputation as a stand-up, hard working guy has attracted laborers to his farm that are more skilled and more loyal that typical laborers.
When the local lord wants advice he invites Jack to lunch or "stops by" the farm. Jack has the undying respect (or envy) of most of the people around him and is a leader in the community. When he speaks, people listen. When another farmer's cow is sick, that farmer goes to Jack for advice. When another farmer's daughter wants to run off and join the circus, that farmer turns to Jack for advice. Jack doesn't know much about fighting (though he can hold his own against any orc) and he isn't a hero but he's the sort of fellow a community leans on.
Make sense?