I think sequins have come a long way over the past few years. When I last wore them, they were splashed all over my costumes for dance recitals or for danceline. After such showy pieces, I tried to remain snobby towards them but the priss-pot in me won and I am loving them right now.
It is possible to walk dangerously close to a costumey look if sequins are not worn properly. I think that the article of clothing covered in sequins should be the focal point. If you are wearing a sequin top, try to wear something less flashy on the bottom. The silver-sequined sweater pictured above would look cute with leather trousers. If leather isn't your thing, then jeans would always be a safe choice.
If sequins are a little much for you, maybe a pair of glitter flats would be a good choice. With a less shiny surface area concentrated on your feet, you will look chic and not so much like a disco ball.
Do you like sequins? How do you wear them?