This will vary from person to person... Hm, generally:
- A statement SOMETHING. Belt, necklace, scarf... just something with large details that really get the inner "you" across to the world.
- Something in a color that lights up your face. Doorknocker earrings? Scarf? Brooch? Neclace? Headband? Sometimes we end up with a top that isn't the best color on us, or we have an all-neutral outfit that needs a touch of cheer. An accessory near your face can change that right around.
- A belt of your choice. I don't know your body type - some gals need high contrast, some need low contrast, some like to cinch the waist, others like to add some curves to the hip line. In any case, a belt is a great way to create some optical illusions and interest in the middle of an outfit.
- IMO everyone also needs a great pair of sunglasses. They save our eyes from sun damage, so we usually wear them often. This means they should be as flattering as possible.
- I keep handbags and shoes in their own category, but if they are accessories for you, then I say at least one neutral and at least one color of each.