Some one I know is writing a book about scientific communication. He'd seen my posters at a conference and asked me for copies of my posters at that conference. He also asked if I had any advice about making non-bland posters. Do I have advice? Of course I do. This is what I emailed back:
I think it comes down to a philosophy of what posters are and who the target audience is. I use posters to provide a high-level overview of techniques and results. Most of the viewer-ship of posters are interested in the topic, but are not themselves performing research in it. So, putting too much detail in posters is pointless. This is unlike an article: I write articles for someone who may discover the article by searching the literature. Such a person is knowledgeable in the field and is interested in the minute details of what we did (so technical details are good). (For example, compare my article on storm-type identification with the corresponding poster).
I recommend starting out a poster by coming up with a 1-minute synopsis of the research. Then make sure that the structure of the poster as a whole reflects it. Then, consider what you would say in a 5-minute explanation of the research and make sure that the poster addresses those points without detracting from the 1-minute explanation. Any detail beyond what you would explain in 5 minutes does not belong in the poster.
Thus, the QC poster (above) ended up mostly being an image collage illustrating the improvement in the QC using the new technique (this is the 1-minute synopsis). For people with more interest in the topic, there's a FAQ that addresses why we did what we did and what the improvements were (the 5-minute explanation).
The 1-minute explanation of the storm-type work (above) would be as a set of steps. So, the main thing you see from a few feet away are the arrows. The captions on the images tell you what the steps are. The images themselves add the 5-minute detail to the listing of the steps.