Flow refers to how easy or difficult it is for someone to read through your poster. You can improve the flow of your poster, and help people read through it faster, but using the following design elements:
Organize by Columns
Many people are used to reading from left to right and from top to bottom. Organizing your information into columns takes advantage of this fact and aids in comprehension. Otherwise, people can get lost trying to follow the information you are presenting.
Use "Visual Grammar"
People are used to following certain design rules without thinking about them. Most people, for example, recognize that section titles in an article are usually a little larger than the rest of the text and may be a different color or in bold. You can use these same rules to help guide people through your poster.
Include Organizational Clues
You can include numbers, letters, or arrows to guide people through your poster. For example, you could number each section to indicate the order that people should follow.
This example illustrates how all three of these rules can be used in your poster: