Older gents are often grateful for the company of a younger woman.  I younger man may may be more critical of paying for anything less then perfection.

Attitude is the biggest issue.  Women generally want to be respected and treated kindly and gently.  Older men seem to understand that more.

You do not have to be a good lover but it doesn't hurt.  This may be an opportunity to learn from an experienced woman if you ask her to teach you.

An older provider may be a better teacher and a better lover then that hot 20 something chick.

A provider I most often recommend to friends is in her 40s and is an awesome passionate lover. (See my review of Vivienne)

Providers prefer to be paid. Beyond that being prompt, courteous and clean all rank very high on their lists.  Some ladies do prefer to see older gentlemen and will state this on their web sites or in their ads but this has more to do with maturity than sexual experience.