I believe every girl should have one denim dress, a black crop sweater, and a necklace chain. You can even wear them together, just like I did! Those are kind of wardrobe staples--very practical, easy goers, and simple. I have worn the dress in summer over a million times alone.
My denim dress is from Gap, my sweater from Zara, and I bought my necklace chain from a silver shop when i was in Bodrum, Turkey, for vacay.