My first cover was professionally designed by the wonderful ebookLaunch team, and, while I loved it, it cost way more than I could consistently afford for each new release, especially with the economic downturn. So I took a gamble, found an amateur artist on a website a friend told me about, Fiverr, for Book II (note: if using this website, please tip generously, as it seemed to underpay its talented artists!). He came up with this, which is absolutely amazing.
https://www.fiverr.com/vikncharlie is the mastermind responsible.