You start with a permitting process. That's right, you want to put up a sign then you go to the city (or online if you're in the 21st century) and you apply for a permit. Then you get a sticker to affix to the sign so that anyone who wants can check that the sign is approved as legal. This is done in neighboring cities, the ones without rampant sign pollution. Fun fact: this was actually done in Dunwoody, but that was when the county (remember Vernon?) was in charge but once the city took over the city was taken over by businesses and well...here we are.
Because of the city supported Uglify Dunwoody campaign, rolling out sign permitting is a start but is far from sufficient. It must be possible for citizens to quickly and easily enforce sign permitting. There needs to be an app for that. Stickers should be like license plate stickers with clearly distinguishable markings indicating type and and expiration date. They should also include a QR code used by the app to pull up detailed information on the applicant, the sign, the sign type and current status (e.g., expired). If the permit is expired an immediate notification will be made by the app to the system and a fine will automatically be issued.
Type, location and presentation would be supported by the app with the inclusion of one or more photos as well as the GPS location of the offending situation. This would require action on the part of city staff, which to date has been willfully absent, but the application will further allow anyone to access the complaint reports and monitor progress, both by the offender and the city.
Equally important is that GPS location can be used to support varying rules, based on overlay districts or specific communities. Not only can the system provide immediate updates to concerned parties but it can provide, in the moment, the status (approved or illegal) to the resident who is concerned about Beautifying Dunwoody.
At the end of the day, only the residents of Dunwoody will determine what is and is not a "Good Sign" and it is incumbent upon a city originally intended to serve those residents to step up and empower those residents.