In our modern-day lives, the sofa is something of a jack of all trades, required to serve a multitude of needs: from sitting to surfing (the web) and sleeping to supping (food).First and foremost, any sofa must be comfortable and cosy. The idea of sitting up straight, in a prim and proper fashion, has long been forgotten. Those hard-cornered, linear sofas are best left in waiting rooms and receptions. At home, make that sofa plump and plush, with a nod to good taste of course. Secondly, any sofa is likely to be a mainstay, something you will live with for many years. As such, it must be aesthetic, long-lasting and functional. Choose wisely, thinking about your space and your needs. Thirdly, treat your sofa as an investment and not as a fashion item.Yes, good design will cost more, but it will not become obsolete after several years and will wear well. Finally, remember that a new sofa will quickly become a familiar piece of furniture. It will be there through the good times and the bad, just like a close and trusting confidant.Here are six new sofa designs for cosy comfort.Pondok SofaThe Pondok sofa by London studio Doshi Levien is part of a new 13-piece ‘Open Home’ collection for veteran British high street retailer John Lewis. The collection is described as a mix of Scandinavian modernism and Italian midcentury design.RELATED: Iconic Modern Sofas That Bring Home Comfort And VersatilityPondok sofa for John Lewis. Image via Dezeen.Soft Modular...