The type and size of font you use is important. Is it legible? Use classic fonts that are easy to read, they are popular for a reason – they are easy to read and understand. Fonts such as Arial and Helvetica are ideal, while creative fonts like Comic Sans or any handwriting or serif fonts are more difficult to read.
Brand guidelines aside, the colour you use throughout your display needs to be easy on the eye; eye-catching not blink worthy. While a single colour can be used as the dominate colour, the colour wheel can be used for complimentary colours (the colours opposite on the wheel work best). Alternatively, popular combinations using black, red, yellow and white have been proven to be successful and are used by some of the largest brands in the world (McDonald’s, Shell, KFC, Coca-Cola, Nike).
Availability of a moving image can have an impact here although you should consider your audience and the time they have to consume the message. Comical animations may not have the same impact in a corporate environment as they do in a school hallway, and long-winded text or videos at POS can be lost if the queue moves swiftly. If you want impact, short, sharp and a combination of animation and static works best.