First, find an attorney who has experience in the legal field you need.
Second, select an attorney who provides a free initial consultation to discuss your case.
Third, take advantage of the free consultation. It will enable you to 1) See the knowledge base of the attorney in your legal area. 2) Most importantly, determine your comfort level in communicating with the attorney. Do you feel comfortable asking questions? Do you feel comfortable with your responses?
Finally, discuss the costs of service. All costs should be discussed with you up front. You don't want unexpected costs to occur later. Remember, the lowest cost may not always be the best. A fee, significantly lower than others in the area, may reflect experience or the bulk handling of cases. Any mistakes may result in significantly higher costs later!