My father, a lawyer is always impeccably dressed.....and drummed that constantly into my head...
I remember as a child, one of our neighbours had a get together......it was on a Sunday and brunch I believe...
My father showed up dressed in a suit, while everyone else was in jeans and shorts......
Afterwards I set to him.......'didn't you feel awkward ?"
He said "On the contrary....I felt great, the others were a bit uneasy....."
While perhaps he over did it, you can certainly never go wrong dressing up, even if not in a suit, a smart pair of pants and shirt, as well as shaving and being clean will go a long long way towards first impressions.....
Hasn't failed me yet !