Choose a Healer like you would any other professional. Ask them about how they work, what are their skill sets.
Do they have testimonials that indicate their success as a Healer?
Are you comfortable with that person, after all, they will be in your subtle field?
Be sure that person is able to convey to you in a language that you understand, how they practice.
Can they explain what is going on with you?
You must trust your Healer.