Yes 'Mam

[FiveDisgruntledMonkeysWit]

My character just got out of a mildly uncomfortable situation in which he needed to address a woman with respect. However, not with that sort of terrified, female Templar or Head Noble respect. I ended up calling her 'miss' and it seemed entirely Un-Zalanthian and awkward. What are some respectful terms you could use for a well-off man or woman who is still, technically, a commoner?

[Rindan]

Their job title is usually enough.  Something like "Thank Senior Merchant Fred" or "Good day Advisor Joe" is a formal way of addressing a commoner.  If you don't know their title, then the best you can do is ma'am or sir.

[John]

look at the OOC boards in the game. It has a post dedicated to titles.