All you need to do yo look early 90's is to find a big (preferably white) t-shirt with some neon or other bright pattern on it and put it on! I chose to cut the arms off this t-shirt so it got a more fitted and stylish look. The glasses are my mums - she wore them in the late 80's. The nail polish - which I call "world-map pattern" - you can read all about here.
Maybe you have an old gym-class t-shirt laying around? And if you were a kid in the early 90's as I was it is a perfect time to get back to wearing them! To style them up you can cut the arms off or tie the front into a knot - there are loads of things you can do to look 90's retro.