A good place to start for
tiny folk, a sofa cushion fort is constructed by placing three or more
sofa cushions together into a
cube and sitting in it till your
hyperactive imagination can no longer focus on the
coolness of your fort, or your
mother tells you to put the sofa cushions back, for god's sake. A fun activity at this time is to
smash your fortress. Preferably as you make
sound effects.
Of course, as you get older and wiser, you can move on to larger, more complex fort designs.