How can I learn how to write a 12 bar blues song?

To learn how to write a 12-bar blues song, study the structure of traditional blues songs, which typically follow a pattern of three lines repeated over 12 bars. Listen to Blues Music to understand the rhythm and feel of the genre, and practice writing lyrics that express emotions and experiences common in blues music, such as heartache or struggle. Experiment with different chord progressions and melodies to create your own unique blues song.