There is a unique and useful tool in PowerPoint that allows you to select multiple shapes and merge (combine) them in 5 different ways, with varying effects.
You can choose
Types of Merges
Union is like laying one on top of another and gluing them together.
Combine is similar, but it deletes anywhere that one shape overlaps the other.
Fragment breaks them into three pieces- the part of shape 1 that doesn’t overlap shape 2, the part that overlaps, and the part of shape 2 that doesn’t overlap shape 1
Intersect is basically the opposite of Combine- it only keeps the part where the shapes overlap.
Subtract depends on the order you select the shapes, because it subtracts whatever overlaps and only keeps the remainder of the first shape. (Choose one shape and then delete the other shape from it.)
PowerPoint already has a couple ways to crop a picture to a shape. You can start with the picture and crop to shape or start with a shape and fill it with an image. If you can’t find the exact shape you want, you can create it. This example is from using a Union Merge on two circles.
Formatting Merged Shapes
You can also format the shapes after merging. For example, you can make the three parts of a Venn diagram differently, and now that they are fragments, you can type appropriate content in each area.
The best part is this is not just for literal shapes from the Insert-Shape menu. It works with pictures and text as well.
This one includes a plant made from combine and subtract, as well as adding a picture as texture to text using an Intersect Merge.