DO be careful and choose an agency which is a member of the Association of British Introduction Agencies.
Member agencies follow a strict Code of Practice.

DON'T be afraid to ask how long the agency has been in business and how many members they currently have.

DO make sure that the people you speak to know and understand your needs;
and get them to explain to you in detail what it is they can do for you.

DON'T be put off by agencies who ask you for lots of identification.
The security measures that they employ are there to protect you and your confidentiality.

DO visit the agency and ask to see evidence of the successful track record, letters of recommendation,
thank you letters, wedding photographs - these are all hallmarks of an agency which knows what it is doing.

DON'T think you will necessarily get what you pay for. Fees vary widely from one agency to another;
the most expensive is not necessarily the best.