After purchasing or creating your template, print it and use to lay out your design.
Cut your foam boards into 5 inch strips.
Following assembly instructions, tape together the back of your mosaic and cut then glue outer pieces together. This part can be tedious and is why I recommend cutting all your foam board strips before starting. You have to make additional cuts but you can work faster.
Fill up your balloons, do not overfill. I would fill a few and see how they look/fit on the structure before completely using all of your supply. I found the small white balloons needed to be a bit smaller.
You'll also want a mix of slightly larger and smaller balloons to give the mosaic depth and to fill in any holes in the design.
Using your hot glue gun on it's lowest setting, apply to balloons and fill the display.
Use your smaller balloons to fill in any gaps.
If securing to a post, fence, etc., use your floral wire and a command hook to loop it around and tie off so that it doesn't blow over.