In formal personalized stationery, you’ll often find a monogram used to represent the sender. A monogram is a design consisting of two or more alphabetic letters combined or interlaced, commonly one's initials, often printed on stationery, embroidered on clothing, etc. You can think of this emblem as a logo used to represent an individual person instead of a business.
Many businesses have chosen to use this type of logo to represent themselves as well. There are some famous businesses that have very recognizable monograms. You can use this type of logo idea for your next client, or offer services that are more streamlined for individuals by creating monogrammed stationery. Here are some famous monogram logos: