Tools and Materials needed:

1. Foam.
I prefer pink/blue 2" insulation foam but I have used the same technique on packing foam as well. One note of caution if you are using packing foam, make sure that the pills that make up the foam are tight together. You should be able to rub your finger over it several times without it flake or fall apart.

2. X-Acto knife.
Keep a few extra blades on hand. Once the blade goes dull it will pull the foam instead of cut it.

3. Ballpoint pen.

4. Real bumpy rock with sharp edges.

5. Your paints (not shown)

Let's get going already!

Step one - Cut your foam to the desired shape/dimensions you want.

Step Two - Using your ballpoint pen draw on your stones. Fieldstone walls are put together like a puzzle. The stones themselves are the pieces. You can make the stones any size you want, any shape you want. Leave about an 8th of an inch (3 mm) between each stone.

Step three - Carve out the stones.
Using your knife, carve out the areas between the stones. Hold the knife at a 45-degree or greater angle run your knife along both sides of the channel. You're looking to make a "V" type cut here. See below.

Trench	Side View
This is where patience is a virtue. If the knife starts to pull on the foam (more then 3 times) change your blade. Change your angle to give the channel more/less depth.

Step Four - The tough part is done so let's paint that sucker. Paint the cement first. I am using my own blend of Delta Ceramcoat here. (Four drops of Quaker Grey to every drop of Toffee brown.) Don't worry if you paint the tops of the rock here. If it's easier for you, paint the whole thing gray like I did.

Step Five - Paint the rocks Dragon Black. Make sure leave some gray between the stones but if you miss a couple of spots that's ok. This is the base coat.

Step Six - Use your jagged rock to rough up the foam.
Take the rock and really press the texture into the foam.

You can do this step now or put it before step four for future projects. I put it here after I paint because the sides that have been cut seem to stay textured with the paint one them.

Step seven - Paint the all the rocks Granite - Dry brush the stones. Be sure to dry brush in different directions. In addition to dry brushing I also used a stippling technique on some of the rocks to make additional texture.

Step eight - paint the stones. Again??? Yes but use different colors. This project I am using just browns. (Volcanic Brn, Woodland Brn and Chestnut Brn). Really water down the colors to almost a wash. Paint as many rocks as you like. I used my finger to swipe some of the paint from one side to the other to add a blended look.

Fieldstones don't normally come in the same color. I have seen white, red, orange and yellow so don't think that browns are the only ones you can use.

Step nine (Optional) - Add the mud/moss line. No matter what type of yard you have mud and debris gets splashed on the wall. I don't know the technical term is but for now I will call it the Mud/Moss line. Use a wash of Volcanic Brn to make this line. For moss I use a wash of Olive Green like I have here.