"Better Call Saul" ended its first season last night, and with year one officially in the books, we can now definitively say the "Breaking Bad" spinoff was anything but bad — it was great, in fact, even as its central character continuously teetered on the edge of good and bad.

The Saul Goodman origin story proves that spinoffs of big, beloved shows can work, if approached with the right creative intentions. It's potentially great news for "Walking Dead" fans, too, as AMC is about to take something akin to the "Better Call Saul" approach to the record-breaking zombie series, in the form of this summer's "Fear the Walking Dead."

With the book closed on "Better Call Saul" season one, and with the "Fear the Walking Dead" doors set to open in a matter of months, here are some of the lessons the "Breaking Bad" prequel can teach the "Walking Dead" spinoff:

Respect the universe…

Nothing that happens on "Better Call Saul" detracts or contradicts the five seasons of "Breaking Bad." Everything that happens in the life of Jimmy McGill, the man who will become Saul Goodman, is consistent with what we know about this fictional version of Albuquerque, New Mexico.

Likewise, "Fear the Walking Dead" has to sync up with what we know about the proper "Walking Dead" universe. Granted, there's a lot of wiggle room, since "Fear" takes place miles and miles and miles away from the flagship series. But certain rules need to stay consistent across the two shows — that everyone's infected with the zombie virus, for example.

Expand the universe…

Not only did "Better Call Saul" add some compelling new characters to the already rich rogues gallery of "Breaking Bad," it also explored existing figures in greater detail — like the fantastic Mike Ehrmantraut episode "Five-O," one of the best episodes of both "Better Call Saul" and "Breaking Bad" combined.

While "Fear the Walking Dead" will certainly add new characters, it's not likely to focus too much on existing ones, given the distance between Los Angeles and Atlanta. Still, it's an opportunity to further explore certain established aspects of the "Walking Dead" universe — specifically, the origin of the zombie outbreak, which looks to be a major focus of the new series, based on comments from the creators and what we saw in the very first teaser.

But don't be the universe's slave.

"Breaking Bad" and "Better Call Saul" are recognizably related, but also different enough to stand on their own. The rise and fall of Heisenberg mirrors what appears to be the rise and fall of Saul Goodman, but they're not note-for-note comparisons, with Jimmy McGill stumbling and picking himself up in considerably lower-stakes situations.

For the two "Walking Dead" shows, the stakes are always going to be high, what with zombies in the mix — but "Fear the Walking Dead" does not need to be a survive-on-the-road story in the same way as "Walking Dead," unless that's the natural direction. It needs to adhere to the rules established by its sibling series, but it needs to stretch out enough to be comfortable in its own rotting skin.

Find the right people.

Between Michael McKean as Chuck McGill and Rhea Seehorn as Kim Wexler, the supporting cast of "Better Call Saul" is so good that you almost — almost — forget about the Hank Schraders and Skyler Whites of the world.

Already, "Fear the Walking Dead" is well-positioned as far as casting goes, with veterans Cliff Curtis and Kim Dickens starring in the lead roles. Will their characters make viewers forget about Daryl and Carol? Maybe, maybe not — but smart money says they'll at least be worth the side trip to zombie-ridden California, given the quality of the actors.

Keep the team together.

"Breaking Bad" mastermind Vince Gilligan and Saul Goodman creator Peter Gould are the head honchos in charge of "Better Call Saul," and their vision certainly translates from the Emmy-winning series to the new show. Keeping those key voices in place while further exploring the "Breaking Bad" universe is arguably the number one reason why "Better Call Saul" works.

Similarly, pivotal players from "The Walking Dead" are making their way to "Fear," like comic book creator and executive producer Robert Kirkman, special effects legend Greg Nicotero, and executive producer Gale Anne Hurd. With the team that made "Walking Dead" such a success also in play for "Fear," there should be a pretty consistent quality between the central show and its California cousin.

Easy on the eggs.

The Easter eggs, that is. While there are winks and nods to "Breaking Bad" along the way, "Better Call Saul" didn't lean too heavily on the Walter White and Jesse Pinkman buttons throughout its first season — and we don't need specific callouts to Rick Grimes and friends in "Fear the Walking Dead," either. Let's keep Daryl's California cousin Danny out of this.

The occasional connection is fine if it makes sense — a video conference from Doctor Edwin Jenner, for example, if there's a scene with CDC officials in the early days of the outbreak — but only if it makes sense.

Nothing.

Maybe "Better Call Saul" is simply the outlier, the rare spinoff series that completely and utterly justifies its existence with a single episode, let alone its first season. There's something intangible and magical about this show, something that defies logic, secret ingredients you just can't place. Like Walter White's blue meth, maybe the "Better Call Saul" formula is so specific, so mystical, that it can't be replicated by anyone else.

Still, it doesn't hurt to look toward such a successful experiment for guidance — and as "The Walking Dead" prepares to launch its first spinoff, it has few better examples to study than "Better Call Saul."