Easy Mirror Drawing in Illustrator
This tutorial will go over how to setup your project for Easy Mirror Drawing in Illustrator. If you are in need of making a symmetrical design without all the copy / paste guess work than you will find this tutorial very helpful and will make it easier in your workflow. Although it is not a set action or tool, it is a very helpful features non-the-less when designing symmetrical type projects. In the end, you will get a symmetrical drawing similar to the one below
Start by opening up a new document in Illustrator and make sure it is a square document like 600px x 600px. Use the Rulers (Ctrl + R / Cmd + R if needed) to evenly divide the document into four squares. This will help you visualize and place your symmetrical art. Use the Rectangle Tool (M) and draw an empty rectangle with a stroke around your artboard. This is very important so we can enable the symmetrical workflow.
To get started, just draw a simple shape or line art. Add some weight to the stroke and change the line shape profile for some variety.
With the line and rectangle in place select them all by pressing Ctrl + A / Cmd + A. Next go to Effect < Distort & Transform < Transform. A window will pop up with some adjustments you can make. Go ahead and check the Reflect X and Preview Checkbox and make sure to put 1 for the number of copies. You will see that you line work is now mirrored perfectly. Select OK to confirm your settings
If you want to just view the artwork you will be working with (aka get rid of the Guides and Rectangle shape), you can do so by expanding the layers panel and turning off the layers you do not want to see. See the example in the image below.
Now you add to your artwork on the left side and every edit you make will be reflected to the right side. If you want to make adjustments, feel free to make them without any worries because Illustrator will automatically make those corrections to the mirrored side of the image.
Play around and edit your image until you are comfortable with the final product. If you use different colors, you may notice that some shapes overlap each other incorrectly. Do not worry about that until the end when you are certain you want to commit to your edits.
To fix the overlapping color issue and break our artwork away from the mirroring system we set up, we will need to Expand the shapes. To Expand the shapes, select all your shapes and go to Object < Expand... in the top drop-down menu. Click OK and you will notice that the lines and all shapes have been broken away from our Mirror Transform. These objects my be grouped together so to ungroup them, simply press Ctrl + Shift + G / Cmd + Shift + G. Once you have all the shapes ungrouped, you can now select the shapes you want to bring forward (Ctrl + ] / Cmd + ]) or push back (Ctrl + [ / Cmd + [).
When your done, your project should look symmetrical and perfectly measured in distance. This is a much easier method and really shows off the details that only a computer measurement system can pull off.
Wrapping It Up
Using this mirror method is a great way to get precise measurement and help speed up your workflow when trying to deliver a symmetrical project. There are other ways of doing so by copying and pasting, but you are risking overlapping or shortening your strokes and although it may not seem noticeable, your eye can always catch the differences if something is not lined up properly.