Clugston grew up in Fresno, California and attended the Roosevelt School of the Arts. After her freshman year, she moved to Oakhurst, California and attended Yosemite High School.

Shortly after graduation, Clugston submitted some of her minicomics to Fantaco, which signed her to write and draw the vampire miniseries Bloodletting. Clugston followed Bloodletting with one-pagers and shorts in Sarah Dyer's Action Girl and Dark Horse Presents, eventually following editor Jamie Rich to Oni Press. At Oni, Clugston produced her manga-influenced comic book 'series, Blue Monday, which debuted in 1999 in Oni Double Feature #11, and which was inspired by her experiences while at Yosemite High. In 2000 Oni published the first Blue Monday miniseries, Blue Monday: The Kids Are Alright.

Clugston has been nominated for three Eisner Awards for Best Limited Series for Blue Monday (2001), and her participation on Hopeless Savages (2002), and Best Writer/Artist-Humor (2002); The Russ Manning award (2000); and a Harvey Award. Clugston was also nominated for the 2001 Lulu of the Year Award by Friends of Lulu for Blue Monday.

Clugston started her career as Chynna Clugston-Major, before her divorce from Guy Major (a colorist and toner on most of her books to this day). Clugston holds an interest in Japanese, Irish, and British culture culture, including mod fashion, britpop, and film. She lives in San Diego, California, with her husband, fellow Yosemite High School alumnus Jonathan Flores, as well as with her Bulldog, Buster.

In addition to Blue Monday, Clugston's other notable works include:

• Bloodletting ... Fantaco/Tundra (1995—1996)
• Hopeless Savages ... Clugston illustrated the flashback scenes. Oni Press (2001), ISBN 1-929998-24-4.
• Scooter Girl ... a miniseries telling the story of two contemporary mods living in California. Oni Press (2003), ISBN 1-929998-88-0.
• Ultimate Marvel Team-Up #11 ... a story about Peter Parker running into the Ultimate X-Men in a mall.
• "Anew" ... a 1940s romance short story in the anthology Four Letter Worlds. Image Comics (2005), ISBN 1-58240-439-9.
• Queen Bee ... a middle school drama. graphix /Scholastic Press (2005), ISBN 0-439-70987-3.
• Strangetown ... about a ten-year-old girl named Vanora Finnar who mysteriously washed onto the Oregon shore in 1973. Oni Press (2006)
• Legion Of Super-Heroes In The 31st Century ... based on the animated version of the DC Comics property, featuring Superman. Johnny DC (2007)