if you print them dont use RGB mode , use that other one CYAN or whatever is called (when you start a new project , you have it in options) and set 300 DPI (dots per inch)
Use flashy colours on black background , it draws attention most.Use HUGE fonts for headline and add some Disco based brushes like ppl dancing and stuff.Add some stripes and you are done.
It is quick and simple , if you are going big , than you better find someone who does that for living.