Using images in your presentations is a powerful way to impart information. People react emotionally to images, which means they tend to remember information longer than if it is presented as text. You could list on a slide, for example, various methods you used in your study.....as illustrated below.
Or, you could illustrate each of the methods using a photograph, as I've done below.
In the second example, the audience not only gets information about what methods you used, but also additional information about what those methods entailed, which is illustrated in each photo. The second example takes the same amount of space and time to show, but imparts a great deal more information and is more memorable. Also, you can more easily explain each method because you have an image that shows the method being used. In this case, I would animate each image to be brought in sequentially as I described each technique. This approach works especially well when the information is complex and/or difficult to envision.
Images are very useful for comparing and contrasting information, as shown right.
I recommend building a good library of photographs that illustrate methods, concepts, habitats, events, and various other things that you might need in a presentation. I usually spend hours in the field simply taking photographs of various aspects of the environment and organisms that might prove useful later.