step 4: execute
Execute you design using Adobe Illustrator.
If you rather do it on paper or board - that's fine too. If you want to do it half and half - go for it!
Download the work file.
Open it.
Here are the tools that you will be using:
selection
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select, move, rotate, resize objects (shapes, lines, text, etc.)
direct selection
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select and edit parts of objects (corners, points, etc.)
shapes
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draw shapes
line
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draw lines
colors
select fill type & color and stroke (outline) type & color
Panels (settings)
swatches
If you don't see it - go to the Menu bar:
Window > Swatches
text settings
If you don't see it - go to the Menu bar:
Window > Type > Character
Create the "backdrop" for your story.
Each shape should have a meaning.
In my example:
Grey lines represent streets, blue rectangle - water.
If you need to add an image - search for pictures with transparent background. Add "transparent, png"to your image search.
convert images
If you want to use an image that does not have a transparent background - look for black-and-white image.
Paste it onto your map.
Make sure it stays selected.
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From the Menu Bar:
Object > Image Trace > Make and Expand
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Use Direct Selection tool.
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Click on white background.
Delete.
Now you have an isolated shape that you can edit.
Select your new shape. Click on Default Colors button in the Tools Box.
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If you want - you can change colors now.
duplicate shapes
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Duplicate shapes without Copy/Paste command.
Use Selection tool.
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Hold Alt/Option key and drag your shape.
implied lines
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Start forming your path based on your sketches and design concepts.
You can add or remove shapes as you work to improve the design.
As you see, at this point I added a few circles to represent lakes.
adding photos
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You can use any shape as a "cutter" for your photo.
You will need to have some unity and consistency in your design.
If you want to create a custom made "cutter" - follow the steps below.
Start with placing a photograph onto your map.
Resize it if needed.
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Use Shape tools and start drawing shapes to form your "cutter".
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The shapes should cover the part of the image that you want to bee seen.
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Now you need to combine all shapes.
Use Selection tool and select all shapes (hold Shift for multiple selection).
Open Pathfinder palette (Window > Pathfinder).
Click on the first button: 
This will unite the selected shapes.
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Select both: your new custom shape and the photo.
From the Menu Bar:
Object > Clipping Mask > Make
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Now you have your photo inside the shape that you created.
You can edit it if you need to or return to the original photo (Object > Clipping Mask > Release).
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Continue working on the design.
If at some point you will realize that the design looks too cluttered, you can start simplifying some elements.
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Continue improving your design.
...more to be added later...