Designing for young adults

I´ve been recently designing a digital product for “young people”.
It is a very misleading concept since for the European Union,which is the founder of the Project, The category of Young People is represented by the 18–35 years old bracket that is obviously too wide definition.
So I´ve started a short research about products and campaigns for young/millennials and I found myself surrounded by wannabe-cool comic sans font campaigns, horribly decorated with silly illustrations . It was a disaster.
Turns out that there´s a lot of old people using the wrong tone of voice when “designing for millennials”, a concept that is wrong itself.
So the questions are: What do the young people eventually like? which online tools they use? Are they different from adults?
Not so easy to solve this issues but there´s a bunch of good stuff around.
Nielsen Norman Group, an agency that conducts “Evidence-Based User Experience Research” has published some research reports (paid):
https://www.nngroup.com/reports/designing-for-young-adults/
https://www.nngroup.com/articles/young-adults-ux/
https://www.nngroup.com/articles/millennials-digital-natives/
I´ve also found a couple of interesting articles:
Stop Designing for Millennials (Harvard Business Review)https://hbr.org/2015/06/stop-designing-for-millennials
If your company targets millennials read now (Fastcompany) http://www.fastcompany.com/3007916/if-your-company-targets-millenials-read-now
How to design Ux for millennials (Webdesignerdepot) http://www.webdesignerdepot.com/2015/11/how-to-design-ux-for-millennials/
Millennials Reveal Their Top Brands, Apps, and Websites of 2015 (INC.com) http://www.inc.com/ryan-jenkins/top-5-millennial-brands-cities-apps-2015.html
These instead are the most used apps by millennials: Facebook, Instagram, Spotify, Buzzfeed, Twitter, Tinder, Youtube, Amazon.
Even mint.com, a personal finance app, is in the list of the top 20 apps with the highest concentration of millennials (yes, it´s a sort of bank).
They all have a minimal UI and a very clean aesthetic, they don´t treat young people differently than adults, no cartoons, no funny fonts, no cheesy tone of voice.
What to do (needs more research):
- focus on UX . Make your product as fast and smooth as possible (fast ≠ easy)
- mobile first. MOBILE FIRST
- clean UI, background color, overlay pictures (REAL FUCKING PICTURES ≠ STOCKPHOTO)