Now I'm not looking for stereotypical or really 'funny / extreme'. I would like to wear something very believable as if it was in that time. Any recommendations ?

60s: drainpipe trousers, black leather jacket, white Tee shirt, or poodle skirt and bobby socks for girls. Plaid or black and white houndstooth could also be worn for a Mod look (after 1964), with either drainpipe trousers and winklepickers, or mini skirts and knee boots 70s: flared trousers, tie dye, paisley, lots of earth tones (brown, orange, cream, beige). Think hippies and disco people

Flared jeans Fitted polyester shirts Fitted 60's or 70's concert t-shirt