All work and no play? It’s unlikely you’d find that adage on the lips of any Hills cast member during the show’s initial 2006 to 2010 run. Still, when it was time to get down to business, Whitney, Heidi, Audrina and the L.A. gang proved they knew how to slip off their party hats, lower their nose to the grindstone and make that coveted SoCal dough.

While the show might have been emblematic of parties at Les Deux and poolside gossip sessions, there’s no denying it taught viewers some valuable lessons about how to navigate (or, in many cases, how not to navigate) the workplace. Whether leading by example at Epic Records or failing to cut the mustard at People’s Revolution, the Hills cast amounted to its own Business for Dummies handbook across its six seasons.

There will be plenty to catch up on when the show returns soon for its New Beginnings installment (starting on June 24), but first, let’s look back at all we learned about the workplace through The Hills.

Don’t cross your co-workers.

While Heidi’s ambition as a member of PR firm Bolthouse was impressive to her boss, it didn’t sit so well with her friend Elodie. When Bolthouse bossman Brent said there was a promotion up for grabs, Heidi threw her hat into the ring, even though she knew Elodie — who was more veteran at the office — was gunning for the job. Ultimately, Heidi got the gig, effectively ending her friendship with Elodie and inspiring some pointed revenge. Moral of the story? Reach high, but don’t step on those who help you on the path to success.

Don’t mix business and pleasure.

It wasn’t Heidi’s fault that Spencer followed her to Las Vegas, where Heidi traveled at the end of Season 3 for an important business opportunity. It was, however, Heid’s fault that she ultimately fell victim to Spencer’s relentless prodding to party. By submitting to the allure of nightlife, Heidi put her career in jeopardy. So, guys? Leave the significant other at home when you’re traveling for work. And if he or she ignores your request, dump his or her ass.

Learn the fundamentals.

For as long as we live, we will never, ever forget the moment in which Stephanie — a new hire at People’s Revolution — hung up on an important client, mistakenly thinking she’d made a transfer. Sadly, it was a harbinger for things to come for Steph, who was eventually fired for failing at simple office tasks. The bottom line? You can’t hit it big if you don’t first learn the ropes.

If you fall, pick yourself back up.

Poor Whitney may never live down her infamous Good Morning America appearance, during which she modeled a famous Oscars gown on live television only to blow the opportunity by proceeding to fall down the red-carpeted stairs. She was devastated, but even fashion pro Andre Leon Talley gave her some valuable advice: Everyone falls, and the more important part is how you get up.

Don’t abuse the perks.

Who can forget the first big Teen Vogue party, at which the interns were tasked with managing the guest list and keeping watch on the door? Of course, Heidi begged to be let inside, and when she was admitted with her pals, all hell broke loose.

Dress for the job you want.

Whitney routinely describes — in interview after interview — how her biggest fashion blunder on The Hills was what she wore to the Teen Vogue offices on the first day of her internship (it was a cowboy-era dress infamously described as “too matchy-matchy”). So learn from her error, and make sure you put your most professional fashion foot forward.

Don’t let the competition dull your shine.

Emily the Super Intern will forever serve as Whitney’s Achilles heel while Whit was at Teen Vogue — the New Yorker had a superlative understanding of the industry, often spoke over her peers and demanded to get her hands on any opportunity that was up for grabs. Emily may have temporarily made Whitney appear sheepish, but Whit also learned an important lesson: You can’t get what you don’t ask for, and speaking up is a critical part of the workplace game.

Be kind, because you never know who you’ll meet.

Gaga, for example! We rest our case (but maybe Whit shouldn’t have called that outfit “tacky”…? Jussayin’.).