Summer is over. Fall is here. And the next thing you know it's October 3rd, which means you're already behind on planning what you're going to be for Halloween. Your costume for Halloween is absolutely crucial and if it's not perfect. it's like social suicide. Here is the perfect guide to picking your Halloween costume according to the rules of girl world.

Animals are THE go-to

You can make any animal look sexy. So throw on a tight black dress or lingerie and some animal ears and you're in business. Everyone knows what you are and it won't cost you a fortune. 10/10 would recommend.

Actually, you don't even have to know what animal you are.

Are you a cheetah? A leopard? A giraffe? A lion? Don't know, don't care. This is perfect for the lazy girl who still wants to be the best looking one there. All you know is that you're wearing a costume and minimal effort was required. #Winning

Scary.

Halloween isn't supposed to be scary, right? Not many people can pull off the scary look, not even Regina George. You either look like a 12-year-old boy or a pathetic excuse for a vampire. Just don't. Do this and you'll end up looking like Cady Herron.

Keep it simple.

There is nothing worse than having to explain your costume. It takes away the effect of the costume and then you feel like you've gone to far. People think you're a zombie bride when you're actually an "ex wife." Don't make it complicated.

Sexy.

"In girl world, Halloween is the one time of year you can dress like a slut and no other girls can say anything about it." Enough said.

Couple costumes.

First of all, you have to actually find a boy who's willing to participate in matching costumes. Secondly, he'll probably pull a Jason and come with Taylor Wedell. But you'll forgive him anyway.

Group costumes.

Obviously, you can try... but there will always be the Regina bunny of the group. You don't want to be her cat and mouse followers, do you? She'll probably kiss the boy you've been crushing on right in front of you. Just saying.

Jocks.

Two words. Aaron Samuels. A jersey can make anyone look hot, whether you're a boy or a girl. You can't go wrong here.

Last Resort: Be Like Janice and Damian.

Screw Halloween, screw dressing up, screw parties. Watch scary movies and eat as much candy as you possibly can.

Happy Hunting!!!