When designing and creating for signage you must consider visibility foremost!
The biggest issue designers often don’t consider is being able to read clearly from afar. Signs need to be read quickly and be bold and simple. Many signs are read from vehicles and are often viable for only a few seconds. Also contrasting colors and limited graphics, images or photos. Do not clutter up signs or use light over flourished fonts.
Give your self a test. Make a 2’ x 2’ sign, post it 30’ away and walk past the sign, Can you read it clearly and easily?