If you're having lots of people over to your home and feel like you don't have enough seating you can make a temporary lounge seat from large plastic buckets, a tablecloth or sheet and large cushions such as couch or futon cushions.
Instructables user Koukalnator used eight plastic buckets wrapped in a tablecloth and topped with the back cushions of her couch to create the lounge seat in the photo above. She temporarily used decorative pillows on her couch.
Since you can usually get free plastic buckets from bakeries (bulk icing) sandwich shops (pickles) or other businesses this can be an almost zero cost solution depending on what cushions you use. If all else fails I bet you could repurpose a cheap cushion-type pet bed on top of four buckets.
Instant Lounge Seats [Instructables]