One interesting and well-done self-promotion identity system that I came across was that of graphic designer Jonathan Shackleton. His logo is a combination of his initials, the letters J and S (mentioned in this article), which I think is an effective way to promote one’s business. This also shows that even the simplest combination of two letters can become a refined and successful logo.
The rest of Shackleton’s branding reflects his style of work and gives the audience an idea of what he specializes in just by glancing at a poster or business card. I think that this aspect of portraying the most information in the smallest amount of time is incredibly important in a self-promotional identity system, especially for anyone who works in a mainly visual field like graphic design. Overall, this logo and identity system is successful because of its simplicity and unification in color and style.
You can view more of Shackleton’s work here.