Ligatures and flourishes (or swashes) will be useful mostly as options for wordmarks and monograms because they are typographic in nature. Indeed, employing either can change an ordinary signature into a wordmark.
Ligatures
Typographic ligatures have existed from the first days when moveable type was invented, carrying over many of the handwriting conventions of the times into the new medium of printing. Letters in the words “The” and “And” were often combined into single ligatures, and dozens of other letter combinations were among the first sets of lead type ever cast. However, as many new sans serif fonts were not designed with ligature variants, the use of ligatures declined by the first half of the 20th century.
Flourishes and Swashes
Another typographic variation that goes well with ligatures is the making of decorative additions such as swashes or flourishes.
Some of these typographic deviations can communicate either an antique or a modern quality. Flourishes and swashes can imply fun and recreation and are consequently popular in certain segments of identity design, such as the food and drink industry, restaurants and rock bands.
Again, the key rule is: do not impede legibility by obscuring letterforms. It is one thing to use convoluted type on a magazine article title, where it can be an entertaining puzzle. That doesn’t work for wordmarks for corporate identities. The whole raison d’être of an identity is to be instantly and easily recognized.
Designing a corporate identity that has to be deciphered, unraveled or decoded is not a viable option. It goes against the very purpose of an identity: to easily identify the party in question. When it comes to people easily reading what you’ve created, you don’t get three strikes; it’s one strike and you’re out. Sometimes designers get so fixated on typographic creativity that they don’t realize that their decorations are conflicting with the letterforms, or that the design contains other visual conflicts like poor contrast.
When used well, ligatures, swashes and flourishes are powerful tools that can contribute to memorable designs with strong and unique visual entertainment value.
Adapted from Logo Design Theory: How Branding Design Really Works