Some sage and valuable advice here man, I agree with all of it and I would also add that shoes are important, it's something people always notice.

In my experience first impressions are seldom wrong, I can only remember one time where I got it badly wrong and the guy in question became a very good friend of mine. He sadly died a few years ago from a brain tumour. He was a real character and a funny funny guy! He'd have you in stitches with his stories.