Add a ground plane
Technically optional, these steps will further reduce noise and allow more current to pass through your circuit making for better overall sound.
You should not move anything on your board after this process. If you need to make changes, delete the polygons and redo the ground plane after you make modifications.
Right or Control click on the edge of your board outline.
From the menu choose Convert to Polygon
Then Copy
A layer menu will open. Choose the TOP layer and press OK.
The top ground plane will look something like this.
We now need to rename the ground plane so that fusion knows to connect it to any part named GND.
The connection will look like a cross.
You should now see the copper plane connect to anything labeled GND
Repeat the process for the bottom ground plane.
Right or Control-click on the edge of your board outline.
This time choose LINE.
Again, choose copy
This time choose BOTTOM for the layer
Notice you now have a blue bottom ground plane.
Right or control-click on the board edge one more time. Choose Polygon Edge N$....
(not Polygon Edge: GND)
Your board will now look something like this.
You're ready to export your file and preview it on the board house site.