I feel uncomfortable asking a provider to give me a reference. Do providers feel insulted? What is the best way to ask for a reference?

It gives me an opportunity to speak with women I ordinarily would not have a reason to thereby expanding my personal network of business friends and resources.

I can't tell you how often a reference check is done in seconds, but the phone call or email correspondence carries on long after the appointment is confirmed or done.
While reference checks are not an obligation but rather a courtesy, many TER-associated providers and services truly don't mind providing them to each other.  It reinforces our support system.

If you are uncomfortable I would suggest that you begin a Date-Check or Preferred411 profile.
Following each successful appointment with a new guest I typically offer to begin a profile for them if they don't have one.  That way they can circulate amongst other companions without feeling as though they're imposing upon me by supplying my name OR they can book appointments off-the-cuff without having to rely upon me being available to provide one.

The only reservation I have in regards to being used as a reference is for significant amounts of time (6 months to a year from the date of the last meeting is reasonable, much beyond that is for me, not- especially if a client has many references to choose from...but often clients will use the most well-known or visible of their references repeatedly because they know that others will accept her name).  

Just ask your provider via email post-session if she is available for references or ask her to provide them online!

Just kidding. I have NO problem helping my fellow man out and helping him down the road to getting laid. I dont feel insulted, why would I? Its the hobby world..the land of bedding that sweet maiden and that dude that you barely know! The more the merrier!!!!!

run for repeat clients and helps ensure safety (at least more so) with the ladies.

greatly appreciated. I do not like when a gentleman assumes that i will be a reference and i get a surprise email from a lady. Respect and consideration go a long way. I prefer provider references above all others because the ladies have first hand experience as to whether or not you're a gentleman.
I never ever mind being a reference. Just please ask me first.

On the other hand...if i saw you more than a year ago, and we only visited once...well then that would be kind of tough to remember. I usually have a 6 month back reference policy. That is unless you're a regular friend of mine.

xoxox
Mea

A special thanks for all the insights and values in these responses--they serve as a great guide for asking correctly for references.