Socially as well as professionally, medical doctors, dentists, and other professionals are addressed by, and introduced with, their titles. People who have earned a Ph.D. or any other academic, nonmedical doctoral degree have the choice of whether to use "Dr." both professionally and socially. If, when meeting people with doctorates, you're unsure how to address them, "Dr." is always correct. If they'd rather the title be dropped, they will let you know.
It's more common for women to use the title "Doctor" socially as well as professionally than in the past. When a married woman uses the title "Dr." (either medical or academic) socially, addressing social correspondence to the couple is a little trickier. If her husband is not a doctor, address letters to Dr. Sonia and Mr. Robert Harris. Her name comes first because her professional title "outranks" his social title. If her husband is also a doctor, the address is either The Drs. (Doctors) Harris or Drs. Sonia and Robert Harris (the order of the names doesn't matter).
In introductions and correspondence, many Protestant clergy are referred to as "The Reverend." While business correspondence is addressed to The Reverend James Norris, (D.D., if held), social correspondence is slightly different: The Reverend (Mr./Dr.) and Mrs. James Norris. In conversation, a clergyman or clergywoman is addressed as Dr./Mr./Mrs./Ms./Pastor/Rector/Reverend Norris.
Addressing a husband or wife who are both "Reverends" follows the same format as a husband and wife who are both doctors: The Reverends Norris or The Reverend Mrs./Ms. Patricia Norris and the Reverend Mr. James Norris. If either of the couple also has a doctorate degree, that person's name would go first: The Reverend Dr. James Norris and The Reverend Mrs./Ms. Patricia Norris.
Today "Esquire" is largely confined to business correspondence between attorneys and justices of the peace. An alternative is to write:
Mr. David Bowman
Attorney at Law
using two lines, no indent, and including the titles Mr. or Ms.
When "Esq." or "Esquire" is used, the name is never preceded by Mr., Ms., Mrs., or other titles such as Dr., and is written David Bowman, Esq. "Esquire" isn't used in introductions: "I'd like to introduce attorney David Bowman/Mr. David Bowman/David Bowman." It also isn't used for social correspondence, as when writing to a lawyer and his or her spouse or addressing a social invitation. Mr. and Mrs. David Bowman is the correct form.
Professional designations such as CPA (Certified Public Accountant) or CLU (Certified Life Underwriter) are only used on business cards or business correspondence. They follow a person's name, and Mr. or Ms. isn't used: Martha Dawes, CPA; Phillip Olner, CLU. If a person has more than one designation, they're listed in the order received: Phillip Olner, CLU, CFP. Socially, use Mr., Ms., or Mrs. without the professional designation: Ms. Martha Dawes.
Every day we run into people who have an official title. The police officer at the desk is Sergeant Flynn; the head of the fire department is Chief Elmore; the club chef is Chef Rossi; the pilot on your plane is Captain Howe; and so forth. When on the job, such people are always addressed by their titles, just as they are when the matter at hand is related to their work. Socially, many don't use their titles, though they may. Sometimes a title sticks: A local judge, for example, who's been called by his title for a number of years, is usually addressed as "Judge" even after his retirement.