Did you ever see a slide whose background was a photo that took up the whole slide? Perhaps it was washed out like a background with bullet points in the forefront. Or, maybe the photo was the main message and was accompanied by just a few words. It looks slick, but it’s really easy.
For the first type of effect, the washed out background, insert a photo. It should be at a high enough resolution that when you stretch it to fill the slide, the subject of the image is still visible. With your photo selected and stretched across the slide, click the Color button in the Adjust group from the Picture Tools Format tab. Choose a light shading from the Recolor group. Then, right click on the photo and choose Send to Back. Now your text placeholders are visible and you can use them to add bullet point content.
The second type of effect can be achieved by locating a photo with a subject that can “float” on your screen. Using the Remove Background tool on the Picture Tools Format tab (first button on the left) remove areas of the photo to isolate just the object. Position and stretch to occupy enough of the slide to make your point, but still leave room for the required text. If the edges of the object look a bit raggedy, choose the Picture Effect called Soft Edges to smooth it out.