Idea concept build _ Sketch a concept, insert clip art or pictures, and use SmartArt to create a foundational visual... the base visual that you will build upon. Then add additional graphic components directly over the foundational visual. Alternatively you can create consecutive slides where you build increased complexity from the foundational slide so that you show how an idea concept develops and progresses layer_by_layer.
Composite photos _ These are photos with text or other graphics superimposed on the photo. I do this a lot with the quotations I post on social media and put into my newsletters. Import a photo into PowerPoint and expand it as large as you can on a slide. "Insert Shapes" and insert a text box onto the slide over the photo. Type the text you want to superimpose onto the photo and set the text color so that it contrasts nicely with the photo as background. Group the components and you have a composite photo.