A crew neck jumper is your easiest route into the look. A rollneck will take it up a notch with all the ease of an open-neck shirt but with extra impact (and, of course, warmth). Alternatively, a knitted hoodie gives a casual air to smarter pieces like a suit jacket or tailored overcoat.
When it comes to your jumper’s fabric, our shout is merino wool. It’s lightweight and breathable, but with its heat-regulating properties it’s as warm as something thicker. Choose a fine-gauge knit in a fairly slim profile so it doesn’t bunch up under your jacket.
As for colour, you’ve got options. You can go for contrast, like a rich burgundy jumper under a navy suit. A black jumper will always look refined under brown tailoring. Or you can go for a trending tonal look, with like-shades layered together.