For the hardshell method, you are going to have less mess putting in the scenery, but getting the desired landform you would like is going to be harder to obtain and you may have to carve some plaster to get the form you desire. There are three basic types of hard shell scenery. The first is the freestand shell. In that, the land form is initially built up by stacking old newspapers up until the very rough basic landform is achieved. Then ither plaster covered paper towls or plaster cloth (The stuff they make casts with) is draped over the news papers the layers are built up to a thickness. (6-8 layers of plaster) until the structure is self supporting. When dry, the news paper is removed from underneath if acess is available, and the hard sell is sceniced to desired finish. The second method is the wire form method. It takes chicken wire or heavy screen, and uses that to make the basic land form. Use blocks of wood to supprot the wire as you form it to the shape of the land form you desire. Attatch the wire to the wood supportd with heavy brads or staples. When you have the desired land form lay over the wires your choice of plaster soacked paper towls or news paper, plaster cloth or paper mache. Build up several layers of the shell and let dry. When dry scenic to the desired finish. The last hardshell method is the "grid" system. For this you are going to have to cut up alot of old cardboard boxes of common weight corrugated cardboard. Cut them into two inch wide strips and as long as you can make them. Cut them off at folds in the card board as they will cause problems when forming the land form later on. When you have your strips soak them in water so that they are pliable. Then take some strips and start at one end of your scenincing area and lay them out in paralell rows going across your area that you would like sceniced. leave about three to four inches of space between each strip. Its not rocket sicence so exact spacing is not critical. Form the card board to desired land shapes while it is still wet. and let dry. When that is dry, take more strips (wet of coarse) and weave that across the srips put down in the prevouse steps in a basket weave pattern. Again leave three to four inches between strips. At the ares where the strips make a criss cross. I suggest you staple them off for extra support. When that mess is dry, lay severl layers of ither plaster soaked paper towles or plaster cloth. When dry. Scenic to desired finish. This method works really well wih cookie cutter style benchwork where they may be little table top surcace in which to secure support for secnic forms.

I hope I have been of assistance to you and wish you luck on your layout.