Keep text to a minimum. Sadly, many posters look like a manuscript mounted on Bristol board -lots of words in a tiny font. If your poster looks like this, print out a fresh copy and submit it to a journal. Posters have a different role. Although they are stand-alone descriptions of a piece of research, they are also advertisements to lure viewers to stop and talk.
Conversations can lead to exciting new insights or approaches.
And, generally, they can summarize their work in a few sentences. It's so much easier to write those sentences on your poster. Try writing your poster using a very large font. This encourages brevity. Start with 24 point.