At the bottom of this post there will be a link to a Google Drawing. You can use that to create your layout for your stage. Once you have it the way you like, download and import it into Unity.
** Go to your paint texture tool, and add the image as a texture.
** Change the texture size to match the length of your terrain, and be double the width. (for example a 500 x 500 terrain would need a texture size of 500 x 1000)
Now just paint the texture onto your terrain, OR if this is the first texture you assigned, it will automatically apply to your terrain.
Your layout will now be on the terrain itself to help you know where to raise and lower parts or you can see exactly where you wanted to place those houses, trees, etc.
Just remember that you don’t have to follow the layout exactly as it is, but this can help new designers with getting used to playing with the terrain. This is EXTREMELY similar to Rick’s idea of inspiration boards around the stage, which is utterly brilliant, I can’t believe I never thought of that! The map I provided is what I used for assignments in school. Hopefully Someone gets use out of this.
Just click the link then add it to your Google drive to modify it. I left a map on there just to show how I used it, just clear out the left side of the image and create your own map