Create a kid's play room. Carpet the basement. Place all of the kid's toys in the basement. Purchase a tea party set or a small castle for dolls. Alternatively, you can buy a life-sized robot to decorate the children's room.
Make an adult's room. Install a bar in one corner of the basement. Add comfortable couches. Purchase darts and a dart board. Decorate the room with paintings perfect for pubs.
Construct a craft room. You will need to move all of your tools to the basement. For example, if you are interested in woodworking, bring all of your supplies downstairs. Also, if the basement is large enough, you can construct more than one craft area.
Transform the basement into another bedroom. Purchase all the necessary furniture like the bed, a bed frame, drawers, a closet, a desk and a bookshelf. Carpet the floors so that it can be easily cleaned with a vacuum cleaner.
Line the walls with bookshelves to make a study. Add a desk and a chair to complete the look.