Costume Design?? Appealing to Target Audience!

So my film opening takes place in the present day. I started thinking to myself... there is not much costume or set design that I need to create since its all happening now. For example, I have a scene that requires a car. I think cars are really important to a lot of films because they establish a time period. Luckily my film doesn't take place in the 1960's... so I don't need cars from the 60's rolling around... and with my budget of $0 that's a nice plus!

Costume design... Here is my dilemma with costume design... My film consists of mainly teenagers and I have a pretty good understanding of how teenagers dress and act.. because I am one. (so there goes another plus!!)                               

Clarissa Explains It All (Show from the1990's)

Typical millennial... Comfy clothing... thats it. 

See.... compare these two... One is clearly
much simpler than the other! 

\

So as you can see, costume design isn't my main focus. How teenagers react to certain situations and how they are at school: always talking in groups, super cliquey, cellphones, Twitter, Vine, headphones, anything, I want to portray that exactly. I watch a lot of shows and movies that portray 80's kids childhood or 90's teens and I really want that feel for my film opening. I want millennials to watch this and be like "Hey I do that!" "Me and my friends do that!" "I have that!" 

I really want to incorporate apps like Pokemon Go and Vine, and Im not sure I can do that yet... I am going to have to talk to my teacher. I feel like I've said this a lot, but internet presence in my generation is huge!!!! But if I cant do the apps, I know I can add some dance moves that have become extremely popular and funny jokes that only this generation will understand. I know my genre is horror/thriller, but in the beginning my only goal is to introduce the main character, the people around her and  her surrounding.