How do you make a homemade policewoman costume?

I'm going to a Halloween fancy dress party and I am only buying a few things (handcuffs, hat, gun, club) as I have a small budget! So I am wearing black knee high socks and heels, but what do you suggest on the top? Tie with shirt? Do I wear a waistcoat/Blazer/cardigan? Remember I want it slightly sexy but no too over the top that my father won't approve.|||If you could find a blue button up dress w/ or without collar, and put a black belt with it, that would work. Don't forget a hat!