Attire
The author covers professional attire.
For men, a single-breasted suit in navy (best choice), charcoal, or black. Choose a white or light blue dress shirt (avoid French cuffs or tab collars) and a conservative tie. Black shoes (oxford), belt, and socks. No hat.
In dress, women are afforded a broader range of options than men for both formal and casual. The author suggests that they should not take advantage of this latitude: dress as the men would dress - being stylish is less important than being taken seriously. To the same end, keep cosmetics and jewelry to a minimum, be conservative with hairstyle and manicure, etc.