Comment by globular-toast

One thing you could to do the cover to immediately improve it is add margins to the title text, especially to the top. The subtitle is also too long, "ever created" is superfluous. And you shouldn't capitalise the H in history; either make the whole thing title case, or normal sentence case (we don't capitalise nouns or use capitalisation for emphasis in English).

Disclaimer: I'm not a professional, but you did ask ;)