Cotton is relatively simple to clean for a natural fibre. Pet hair can be removed either through vacuuming with a soft brush extension, or by donning a rubber glove and rubbing your hand over the fabric. This should ball up the pet hair into easy-to-grab clumps - though, a lint roller will work just as well. Removing the cushions and beating them regularly should also help plump them up and remove inner dust.
Spots of stains can be removed with a simple cleaning mixture, lightly dabbed using a cloth - take a teaspoon of dish washer liquid and a teaspoon of white vinegar in 250ml of warm water. A teaspoon of baking soda can also be added. This mixture should be enough to remove stains - however, always remember to do a spot test first to see if any discolouration will occur! It may appear slightly darker in cleaned spots until it has fully dried.