Many times it is not the structure of the furniture itself, but the cushions that make something look bad or feel uncomfortable. Instead of buying a whole new piece of furniture, look into cushion replacement. You can get the foam and material and make them yourself, or you can have a professional do it. Either way, it will be much cheaper than buying a new chair or sofa. You could also do this if you just want a change to the look of a room, or to match another piece of furniture.
It can be a good idea to have a new custom cushion made for anything that gets a lot of use every so often. The cushions can hold a lot of bacteria and disease over time. Trying to clean them to get rid of this will usually only result in some pretty smelly seat cushions. Getting new ones will help keep your family healthier. If you notice everyone seems to be getting sick more frequently, think about changing your cushions. This is especially important if you have young children or older people living with you who are easily susceptible to disease.
Having custom foam cushions made to fit your furniture is much easier than you would think. The important part is getting the measurements right. If you are able, it might be best to take one of your old cushions into the place you are buying the new ones from to have them doing the measurements. If you cannot do this, be sure to measure everything two times.