One of my hobbies is making models, especially war games terrain. I made this model about three years ago, but recently found instructables. I was interested in making a trench model after learning about WWI in school. After some brainstorming and many google images searches, i started gathering supplies.
I didn't take pictures during construction, so all are recent.

Step 1: Materials

Most of these materials i already had around from previous projects.

- Polystyrene (home depot)
- Foam core (local craft store)
- toothpicks (I used two boxes for this board)
- double sided tape (not shown)
- corrugated cardboard (not shown)
- hot glue gun, glue sticks (not shown)
- a lot of paint
- sand, pebbles (hobby store, the beach)
- paintbrushes
- hobby knife (not shown)
- hot wire cutter (serrated knife can be used if not available) (not shown)
- card stock (not shown)
- black Sculpy clay (not shown)

Step 2: The Base

I used a 20X16 piece of foam core as a base that I left completely intact. The layer of polystyrene was cut to make the trenches.

I first measured the base of the models i would use on the terrain. I then planned out the trench system with a ruler and a sharpie. I market the pieces I would cut out with an x.
I then used the hot wire cutter to cut out the basic shape of the trenches.

The next step is to round the top edge of the trench wall. I used a hobby knife and the wire cutter for this step.

When you are sure the pieces are the way you want them and hot glue them to the foam core.

as you can see the wire cutter is much smoother than the knife.

Step 3: Trench Walls

This step takes a really long time, i recommend music or tv.

1. cut out pieces of regular printer paper the same height as the walls, and the length of the toothpicks.

2. cover one side of the paper completely with double sided tape.

3. place the tooth picks on the tape horizontally.

4. cut the whole fence to the desired length and glue to the trench wall.

5. add vertical toothpicks every couple of inches.

Step 4: Craters

These are really cool looking and easy to make.

1. Roll a piece of black clay into a ball, and then a longer shape, then into a doughnut shape.
(does not have to be black, but if the paint chips you don't want a bright color showing through)

2. Mold the clay into the shape you want on a cookie sheet. Bake as directed.

3. Glue to the top of the foam core.

For bigger craters it looks cool if you carve away some of the polystyrene to make the craters deep.

this picture is of a crater i made for an alien planet terrain board.

Step 5: The Bunker

I just cut out four identical pieces of card stock and glued the edges together. I cut out a door on one side and a gun slot in the other. I made the top (not shown) by cutting out two squares of card stock, one a little smaller than the other, and gluing one on top of the other. I did this so that the top wouldn't fall of.

Step 6: Add Details

I added details like corrugated card board(sheet metal), extra toothpicks(broken boards), and others to make it more unique.

Step 7: Sanding

I recommend doing this step in sections so that the glue doesn't dry before you put the sand on.

1. paint everywhere that you want to be covered in sand with a mixture of two parts pva glue, one part water.

2. lightly pour sand onto the glue and wait for it to dry.

3. Tilt the board and tap it lightly until all loose sand comes off. Collect the sand on a newspaper and keep for later projects if you want.

Step 8: Painting

Don't use spray paint! it will melt the foam

1. Paint it black!

2. I first pained the dirt areas dark brown

3. lightly dry brush the sanded areas with a lighter brown or tan color.

4. Paint the toothpicks a wood color.

5. paint the bunker grey, highlight the edges with a lighter grey or white

6. paint the metal parts silver, some rust color.

Step 9: Sand Bags(optional)

1. use sculpey clay to make the sand bag shape

2. press a piece of fabric into the clay for the texture. I used a dish towel.

3. use multiple bags to make a wall, then bake as directed.

4. Paint brown, dry brush light brown.

I didn't glue them to the board so i could move the bags around.

The picture is from before they were painted.