Nailpolish is one of the best obsessions, in my opinion, since it’s a ridiculously fun and (fairly) inexpensive way to stay on-trend each season. Note the aforementioned word “fairly” because if you buy, say, thirty polishes a season, that can quickly add up cost-wise too. If you have friends who you’re rather certain are nail fungus-free (sorry to go there, but it’s true), may I suggest a seasonal polish swap? And I actually really, really love drugstore brand nailpolishes: Sally Hansen Complete Salon Manicure is my favorite. The brush head fits my nails perfectly and I have literally applied the polish in the back of a moving taxi (en route to a fashion show!) effortlessly. I also love L’Oreal Paris’ colors, they’re always on trend and the formula is super shiny.
And, as for your second question, depends what industry you’re applying to. Finance (& similarly stuffy ones): be low-key. Fashion: go for it, but exercise chic restraint.