Open your image-editing software and create a new file. Change the drawing boundaries to 24 inches wide and 36 inches high and do not place images or text within 1/2 inch of the poster edges. Select the text tool and create a title for your poster with a font that is 2 to 4 inches in height. The title can run along the top or bottom edge or, more creatively, on a diagonal or along a side. The title text can vary, but it should include "Imagination." In addition, choose a color for the title; although black is common, try other colors, such as red, orange or purple, but avoid light colors, such as yellow, unless you make the background a dark color.
Copy and paste your supporting images and text into the poster. Start with the main idea image for the poster; this should be larger or take a prominent position on the poster, such as at the center, at the top or superimposed on the title. Add the text -- 1/8 inch to 1/2 inch tall -- and other images evenly around the poster surface. The text can be any color, but avoid light colors on light backgrounds, just as with the title. Use tools like "Feather Selection" and transparency to provide depth for the images, and don't be afraid to overlap images that are related. Although imagination provides limitless options, limit the text, other than the poster title, to only one or two sizes and styles -- you do not want to confuse or irritate the viewer with too many typefaces. Save your image as a PDF, JPG or TIF.
Send a digital copy of your poster to a large-format printer, printing the poster on bond or semi-gloss paper. Alternatively, print on solid board, such as PVC or vinyl. If you decide to print on semi-gloss, allow the ink to dry for 2 to 3 hours before handling the poster, and apply a thin layer of spray fixative to the poster's surface.