"You'd look hotter if you dressed older", Girls how do I dress older? (Guy)

I'm 19 and I'm a first year in Uni here in Ireland.
Recently, a group of us we're talking about me using an older persons ID for the laugh to see if I would get in. (I'm legal age, but we wanted to see if anyone would notice since it looks kind of like me)

One girl said, "I bet it would work, if you dressed a little older I say you'd get in. You'd look hot actually.."

For going to lectures I usually dress in, joggers/trackies, t shirt and hoodie.
For going out, I usually wear jeans, a t shirt, maybe an open shirt over it, a shirt, or a jumper. I usually stick with Converse or Vans Old Skools.
I get compliments on how I dress.

My interpretation of what she meant by dress older look hotter, is;
Ralph Lauren, Jack Wills, Ted Baker. Or basically Ivy League style.
Jeans, button up, a cardigan, jumper and shirt, chelsea boots. Basically someone who looks like they're on the Lacrosse team or play Polo.
What do you think?

I'm 5'8, fairly athletic build (probably carrying something extra) and my hair is like this; http://f.tqn.com/y/mensfashion/1/S/o/J/1/102295654.jpg

What do you think?

girls like menwho dress in nice designer clothes whether they'll admit it or not. Anyway its all in the personality anyway though looks definitely do matter

i'm a girl and I definitely don't

yes but most girls do perfer someone dressed well rather than someone who is not

I love men who dress well but to me dressing well doesn't mean "ivy league style" and designer clothes

What would you consider well dressed?