A blazer does not have to mean office. Think of it as the piece that gives shape to whatever you were already going to wear.
Day one: polished
Wear it with a fitted knit and trousers. Keep the shoe simple and let the clean lines do the work.
Day two: casual
Put the same blazer over a ribbed tee with denim. Push up the sleeves slightly and choose a flat or sneaker. The contrast is what makes it work.
Day three: evening
Layer it over a simple dress or pair it with a fluid midi skirt. A little shine in the fabric or jewelry shifts the mood without changing the blazer.