Use a ruler and razor knife to cut out charts, graphics, photos and text. Connect the text to the graphic elements. If a paragraph refers to a diagram off to the side somewhere, say so. Viewers can't read small type from a distance. Use 18-point type or larger.
Variety is important.
Think about your information. Edit your copy ruthlessly. As you jot down the elements you want to include on your poster, group together key or related information. Think about ways to convey those ideas as a unit. Creating design unity OK, your research is done.