Step 1 - Create Your Document
Open up a new document 500x500 and fill the background white. Set your foreground color to #ffffff and your background color to #a2a2a2.
Step 2 - Create Your Brushing
Select the brush tool and grab the grass brush. Brush all over the layer till it looks something like this.
Step 3 - Create Your Next Layer
Create a new layer and fill it #2b231b. Set the layer mode to color burn. You should have something like this.
Step 4 - Merge and Duplicate Your Layers
Press Ctrl+Shift+E to merge the layers. Then duplicate the merged layer (right click>duplicate layer.)
Step 5 - Flip Your Layer
On your duplicated layer go to Edit>Transform>Flip Horizontal
Step 6 - Lighten Your Layer
Set the layer mode to lighten.
Step 7 - Merge and Duplicate Your Layers
Merge all layers and duplicate the merged layer. Then go to edit>transform>flip vertical.
Step 8 - Linear Dodge and Completion
Set the layer mode to Linear Dodge, and your done! It should look something like this:





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