Bikini tops: The best way to stay cool. Bikini bottoms: The best way to get grass burn on your rear-side.

Photo by Jordan Graber.

Flower bikini tops are always in season.

(Photo by Jay Dryden)

Yes to masks. Anytime, anywhere.

Photo by Jordan Graber.

Yes. Don't be afraid to stand out in a crowd. All your friends will find you.

Mike Prokop. Photo by Jordan Graber

This outfit is awesome for everyone but the woman wearing it I would imagine. Hot.

Photo by Joey Guerra

Lederhosen. Because, of course.

Photo by Korrie Cooper Brown.

That looks comfortable.

Photo by Andy Olin

Your wardrobe will get wet. Be prepared. (Todd Spoth / For The Chronicle)

Shades and a large hat are a must. Well done Willie Nelson.

Photo by Jordan Graber,

Please note: If your name is not Morris Day or The Time you are not cool enough to wear this suit outside, in the summer.

(Photo by Jay Dryden)

This T-shirt is acceptable anywhere, anytime, but especially at ACL.

Photo by Andrew Dansby

The bigger the hat the better.

Kelsey Rogers and Morgynn Hayner. Photo by Jordan Graber.

Be prepared to throw out your wardrobe at the end of the day. That's the only way to get rid of those stains.

Photo by Todd Spoth.

Short shorts are always in at Summer Fest. Also, be careful where you sit.

Photo by Andy Olin

Masks are good for everyone.

(Photo by Jay Dryden)

Stand out in the crowd. Always good. (Todd Spoth / For The Chronicle)

DIY accessories: you will need one helmet, green spray paint and many nails.

Photo by Andy Olin

Please note the hat that doubles as a rain gaurd. Smart, not stylish.

(Todd Spoth / For The Chronicle)

Bring your own shade.

(Todd Spoth / For The Chronicle)

See what this woman is wearing? Hydration is the best accessory ever.

Photo by Jordan Graber.