Just because you are creating physical signs and pieces created through processes like custom screen printing doesn't mean your business should neglect the possibilities of digital sharing. Devising images that go well both on vinyl signs and in JPG format on the internet can lay the groundwork for a campaign that really takes off.
Take a look at the campaign for the upcoming film in the Teenage Mutant Ninja Turtles franchise. It's been heavily hyped with a trailer that was circulated around the web, so now it seems obvious that the reveal of the poster images would get as much attention, as it was posted on /Film.
However, these days the "poster" is just one aspect of the design, as many filmgoers might not actually see the posters themselves until they go to the theater. So how does a company design an image that you can stick to throughout the various media that you employ for your campaign?
When it comes to these posters, the tactic seems to have been emphasizing the characters and giving viewers a clear look at what they want to see. This seems to be following on the intense speculation that's surrounded the whole project and presenting this front and center as a supplement to the trailers and other materials.
The process of rendering an image for the vinyl signs you use may be different than the one you use to try and create a viral image. But the basic idea should be the same: show your customer base something positive and distribute it in a way that gets people talking. This emphasis on images that many people will want to recognize can also lead visitors to take pictures of the signs around your place of business, which could also increase interest.