You can also first visit our recommended agencies that you can find in this topic.Write a detailed introduction letter (preferable translated in Russian), to receive a detailed reply of the woman If you write your Russian lady for the first (introduction letter) time, please write a detailed letter about yourself.Only use real, professional and verifiable agencies.
These are organizations that will use methods to keep you as long as possible as a paid customer, or those who ask far too much money for their services.
For the woman it's important to see that the man who is writing to her is serious about finding a new partner.
To be very serious in your intentions and to be very open to her, gives you a response which you can analyze as reliable or not.
Perhaps their introduction or 'About-Us' pages or other relevant pages could give you some background information of this specific Dating Agency, which could give you a 'good' or perhaps 'wrong' feeling about this site and their services.
Also try to find out if they are a member of the Anti Scam Program.