Papercrete is an amazing, simple material gaining acceptance  over the last decade by alternative builders, and even code officials across the US.   It's almost free to build with (you buy Portland cement by the bag), there are MANY versions, and some do not include the cement, creating a "paper adobe" safe to handle with bare hands.

This material  is easy to sculpt with, make blocks, use as a mortar, a plaster for walls, as floors, as wall insulation, as roofing insulation,  for arches, privacy walls, garden walls,  patio floors, used for animal shelters, for dog houses, and childrens' playhouses too.

Start with a small sculpting project , or insulate your pet's outdoor shelter, maybe insulated the garage walls.

Papercrete can be stunning or a horrible mess...it all depends on the detail and attention you pay. When used as insulation no one will see it. As adobe blocks they can look like stacked stone, or  if crooked and ill-placed,   a plaster  coat can make the wall as smooth as you want.  Your creativity is unlimited.