As suggested by the name, a V-neck jumper has a v-shaped neckline. Complement a V-neck jumper with a formal shirt. You can wear this with or without a tie, depending upon whether you are trying to achieve a smart-casual or just casual look. Keep both the collar and the cuffs under the sweater and the shirt tucked in. A V-neck jumper also goes well with a button-down collar or a crew-neck t-shirt. For the best effect, avoid low-cut V necklines.