Contact the ladies you reviewed and ask if they will provide a reference. If not, determine how much information you are willing to share and find a newbie friendly provider who will accept it.

Get verified by a verification service like P411 or Date-Check to start. From those boards, search for Newbie-friendly providers and start seeing a few. Then as you are leaving your next appt, get in the habit of asking the lady "Would you mind if I use you as a reference?" I would think most would be happy to oblige as long as you were respectful and a gentleman with them.  

After a few times doing that, you will have a nice set of references so that you should be able to see whomever you want. The only caveat is that many providers will only provide references if you have seen them in the last 6 months so you have to keep your references pretty fresh.  

Good luck.

As a newbie-friendly provider, I always offer numerous ways to go about verifying.  Getting on P411 and Date-Check are definitely helpful, but most ladies are going to want a real full name and phone number regardless if you're new or not.  Those services are a lot more anonymous.  If you're willing to disclose information concerning employment (this is an option for newbies or for those who don't have references) or other personal information, it'll be a lot easier in the long-run.  I don't know how prevalent RS2K is in the DC area, but Chicago gals use it a lot.  It's a verification service as well, but it requires your full name and phone number.  Verification is painless with them as well.  

You've seen providers recently though, and written reviews.  Simply ask those ladies if you can use them as a reference.  It's not that difficult, and if you had a good experience together, I'm sure she'd say "yes".  

Take care and have fun!

...pm or email directly if you'd like.

I am flexible.. careful but will work with you..