They told me when I had my 12 week Nuchal scan, they were 90% sure I was carrying a boy and this was confirmed at my 20 week scan.
I've been told if you hold a ring or needle suspended from a piece of sewing thread you can tell the sex. If it swings side to side, you're having a boy and if it travels in a circular motion, then it's a girl.
When I tried this, it went circular for a irl, so probably not accurate. Going by Redcrx's list, I have the traits which means boy. My skin is clear, I'm off sweet things, in favour of savoury, but have heard the opposite, that if you're all bump, then it's a boy, which I am.