For back-to-school fashion, grunge lovers can rejoice: The '90s are back, with an abundance of denim (ripped and layered), flannel and chunky mules.

Or make that the '70s, with a reboot of flared jeans and burnt-orange hues.

Or is it the '80s bringing the bomber jacket back?

Styles for students this fall are going back in time to borrow trends and update them for today, proving that Taylor Swift was right: We'll never go out of style. Just look at Pokemon. The '90s fad is not only a ubiquitous game app, but it's popping up in back-to-school styles as well.

Physical stores still reign as the preferred method of back-to-school buying. And a National Retail Federation survey found that families with children in grades K-12 will spend an average of $673.57 this back-to-school season, up 9.6 percent from last year.

Specifically, 95 percent of respondents said they would purchase clothing, for a grand expected total of $9.54 billion nationwide.

So, if you're going to drop big bucks on back to school, you might as well get in on the hot trends.

[naviga:h3]DENIM[/naviga:h3]

Students can't get enough of denim. How to get more in your wardrobe? Layer it.

Denim on denim, long the taboo of the fashion world, is coming (back) into style. The style works best with lighter shades — no heavy denim jackets paired with dark denim jeans. Chambray shirts fake the denim look with flexible, breathable fabric. Look for denim pencil skirts as well.

But denim doesn't have to be as unforgiving as the era of the skinny jean. The bootleg and flared styles from the '70s are making their way back onto the racks, and the retro distressed, torn look gives an edge to the classic fabric. Dust off those jokes, dads — you'll once again be able to ask, “Did you get a discount for the holes?”

[naviga:h3]BURNT ORANGE[/naviga:h3]

The color orange screams fall — gourds, leaves and, of course, pumpkin spice lattes. Incorporating it into an outfit automatically puts you in the season, but the brighter burnt orange on racks today also effuses the carefree summer sun beating down on students as school begins.

Men can have the best of both seasons in orange shorts. For women, the color pops up in accessories, like scarves and earrings, but you can also find simple tank tops and T-shirts embracing the trend. For a more dressed up look, try a two-piece burnt orange skirt and crop top.

[naviga:h3]BOMBER JACKETS[/naviga:h3]

It has been three decades since bomber jackets last permeated fashion culture, but the '80s trend is enjoying another style moment (thankfully, without the big hair and parachute pants). The bomber is the perfect transition between summer and fall — not as heavy as a puffer jacket but just dense enough to guard against the chill of October evenings.

For men, more popular than the bomber is the moto jacket, a motorcycle-style jacket made of leather or faux leather.

[naviga:h3]KIMONOS[/naviga:h3]

One of the more interesting trends this year comes from across the Pacific: kimonos.

They're not the full-length garb from traditional Japan but instead a cardigan-like wrapper, typically adorned with florals. The kimono instantly adds polish and some flowing, 1970s dreaminess to a summer outfit, and its lightweight fabric keeps you cool as the summer comes to an end.

[naviga:h3]MULES[/naviga:h3]

Ankle boots with wide heels aren't a new trend, but don't expect them to go away anytime soon. The “new” trend? Mules, in all their '90s glory.

While the original iteration of the shoe style was closed-toe, this season's mules let toes see the light of day. As fall approaches, the trend might move back to its original look, but for now, feel free to incorporate either style.

[naviga:h3]TECHNOLOGY[/naviga:h3]

Technology is the ultimate cool factor, and you can find technology-inspired trends in clothing and accessories. Stores geared toward younger consumers have stocked up on emoji-themed pillows, patches and stickers.

And with the explosion of Pokemon Go, there will be more '90s throwback in apparel.

[naviga:h3]OTHER TRENDS[/naviga:h3]

Other notable trends include flannels, monogram backpacks and layering.

An overwhelming feel of this season is casual, so no need for teenagers to break out their heels to wander the school halls.

Fashion seems to be moving away from the skintight era into a looser, more romantic style.

So, go ahead this school year — relax and feel the nostalgia.