In addition to offering flexibility within a space, open-plan living can also create the illusion of more space, making smaller rooms seem larger.
Creating fluid but defined spaces within an open-plan is key. The use of rugs beneath furniture groupings can be a great way to designate zones within the space. As you can see in this design, overhead lighting such as decorative pendants can also be used to draw attention to the center point of defined spaces like over this kitchen island.
Most importantly, an open concept must have a natural flow. Ensuring there is enough floor space between zones will allow people to move freely, especially around large furniture groupings.
Open-plan designs have no definitive style. Decor and furniture styles are determined by the client's or designer's vision. The style should, however, complement the rest of the house!