Even if you haven't seen the show, you've almost certainly heard of HBO's hit Girls, created by and starring Lena Dunham.

The show follows four 20-something women living in Brooklyn and all that that entails. Because it's aired on premium cable, Girls doesn't pull any punches, and has a lot of adult content. But at the same time, it also has some great lessons for designers and developers.

Here are ten of the best lessons Girls has to offer. There are more, for sure (just check out the set and costume designs for some great visual inspiration), but you'll have to check out the show for yourself to see them.

1. Backing from a heavy-hitter is invaluable

One thing Girls had going for it right from the get-go was Judd Apatow as one of the executive producers. In case you've been living under a rock for the past few years, Apatow is the Producer/Director/Writer behind films like Knocked Up, Superbad, The 40-Year-Old Virgin, Step Brothers, Pineapple Express, and Bridesmaids, among many others. In 2007, Apatow was ranked on Entertainment Weekly's The 50 Smartest People in Hollywood list, so any project he gets behind is probably going to do well (or at least get sufficient support).

What this illustrates is that if you want your project to be a success, to get the support it needs, and to have a fighting chance, it really helps if you can get an industry heavyweight to back you. This could come in the form of a testimonial, a recommendation, or actual involvement. It means that if you're working on a project for a specific company, getting the CEO, president, or other executives on board means your work will go a lot smoother and be a lot better received.

2. Being a diva gets you nowhere

In the first episode of Girls, Hannah (Lena Dunham's character), acts like a complete diva when her parents tell her they're cutting her off. She basically throws the equivalent of a 20-something temper tantrum.

And you know where it gets her?

Nowhere. Her parents don't relent, and I'm pretty sure her mother's opinion of her goes down a notch or two.

If you're working with clients and they want you to do something you're not particularly fond of doing, don't act like a diva about it. It won't get you anywhere, you'll lose the client's respect, and no one will come out of it better off.

Instead of being a diva, think of ways to explain your position, or ways you can compromise with your client.

3. Design what you know and understand

Lena Dunham knows what it's like to be a female in her 20s, fresh out of college, living in NYC. And because she knows the material inside and out, there's an authenticity to it, that would be lacking if the show was written by a 40-something man from middle-America.

When you're working on a project, make sure you have some understanding of what the project is actually about. If you have no experience in a certain industry or subject, your designs might not be as good as if you had at least a basic working knowledge of it.

That means, too, that if you're looking for a new personal project, think about areas where you're already knowledgeable. If you worked in restaurants for 20 years, then think about sites or apps you could build around that industry. If you've never set foot inside a designer boutique, then designing a site or app that caters to fashion designers or their customers might not come easily to you.

That's not to say that you have to be experienced in whatever industry you're designing for. There are plenty of successful designers who design for industries they've never worked in. The key is to make sure that you gather enough information to still be effective.

4. You don't need diversity to succeed...

…But that doesn't mean you won't catch a whole lot of flack for not having it. Girls has gotten a lot of criticism for not having a very diverse cast, especially in Season 1. Season 2 has seen the addition of at least one non-white character, but it's almost certain that the criticism will continue from some corners.

While diversity in design can be interpreted in its most literal sense (including only one race or ethnic group in site graphics), it can also apply to designing just for your target demographic. If your target demographic happens to be of a particular race or nationality, then you should design for that group. Sure, you might be criticized by some, but in the end, the design has to serve its purpose well.

5. Controversy is good promotion

Girls has been surrounded by controversy (mostly on its lack of diversity, though there have been other criticisms as well) since before it even aired. The show's controversial elements have been covered in virtually every major blog and news source likely to be frequented by the show's target demographic. In other words, they've gotten free promotion on virtually every site they could possibly want coverage on.

Is this controversy likely to cost them some viewers? Maybe. But it likely attracts a lot more.

Now, just remember that with any good controversy, there have to be two opposing, possibly valid viewpoints. It's not the same as bad publicity. There have to be two sides who are at least somewhat equal (if 95% of people think something is horrible, then you probably want to avoid it). Otherwise, it's not controversy, it's just attention-mongering.

6. Contrast is important

Contrast is a well-established design principle. But Girls is a great example of why it works so well. The four main characters are all very different, and yet they're all great friends. They work well together because of their differences, and it provides a lot of opportunities to keep things interesting.

That's why contrast is important in design: it creates interest. And the right balance of contrasting elements creates something that you can't stop looking at (or watching).

7. It's okay to be eccentric and nonconformist

Jessa is one of the most interesting characters on the show. She's also the most eccentric and nonconformist of the bunch. In the first episode, when she's introduced, she admits to not knowing that Sex and the City is a TV show as well as a movie, and then confesses that she's not on Facebook.

Considering she's a 20-something woman traveling the world, it's very nonconformist and eccentric for her to be so out of touch with what her contemporaries do. But as I already mentioned, she's by far one of the most interesting characters on the show.

Don't be afraid to go against the grain with your designs. While there are some conventions that should be followed, there are others that can definitely be broken if you so choose. You may find that it makes your designs way more interesting and effective.

8. Embrace a sense of place

New York City serves as a kind of character in and of itself on Girls. And that strong sense of place really grounds it in the real world, and makes it both more relatable and aspirational (how many 20-somethings would love to live in the Big Apple?).

While this definitely works best for sites and apps catering to a local market, it can be applied to larger companies as well. In either case, creating a sense of place in your designs can ground your visitors or users. Depending on where the site's owners are located, or where they have ties to, you may really want to capitalize on the location. After all, if you're creating a site for a French restaurant, then you should really consider giving the site a French feel, or highlighting a specific region within France in images and other aspects of the site.

9. Use a manifestation board for inspiration

Soshanna is probably the most manic of the characters on Girls, but she does offer up some very good advice: using a manifestation board for inspiration.

Keeping a board with visually inspiring images and resources can really help if you're feeling creatively blocked. And the great thing is that sites like Pinterest make it easy to keep a virtual board (or many boards) and find images to include.

10. A niche audience is a good thing

Girls gets significantly less than a million viewers a week. But they're a niche show on a premium cable channel, subsidized by subscriber fees. If Girls was on a major broadcast network, it would have been canceled long ago. But since they're on a network that doesn't need millions and millions of viewers to make a profit, they can get by just fine on the viewers they have combined with DVD and other income streams.

Creating a niche site or app has always been touted as the most desirable route. You don't need millions of visitors, you just need enough of the right kinds of visitors to make you profitable.

This also relates directly to the concept of "true fans". A thousand true fans, it's been said, make it possible for an artist to live off their work. Girls works on a similar premise. They don't need millions of viewers, because the viewers they have are passionate about the show. They are true fans. They tell their friends, they buy the DVD's, the pay for a premium cable station, and they'll likely purchase future projects from Lena Dunham.

So what can Girls really teach you?

There are so many lessons to take away from Girls. Probably the most important lesson, though, is to realize that you can learn lessons about design and gain inspiration from a ton of different sources. All you need to do is open your eyes to it.

What other design lessons can you take away from Girls? What other shows have taught you design lessons? Let us know in the comments.