Hello sir!
I, being a new freelancer, do not really have an experience to support my proposal, but being involved in many extracurricular events and coming up with t-shirt designs for the respective events, I can assure you that quality won't be compromised.
Your project demands t-shirt designs for young people. This broadens the design spectrum by accepting both lettering and artwork designs, being funky, stylish, cool and having a message at the same time. This allows me to come up with a variety of not-so-ordinary designs, as per your demands and requirements. I'd use photoshop for the designing. The t-shirt would include designs on any of its part (front, back, sleeves), wherever you want them to be printed. You may provide me the color schemes for the t-shirt and the design both and I'd try my best to come up with T-shirt designs that would complement your thoughts and demands about it.
Please feel free to contact me for further details.
Regards.