Another one of my favorite things to draw on Procreate is digital art of photos. This type of art has gotten super popular recently.
Here is an example of a photo of me at a sunflower farm.

The very important part to keep in mind is the use of layers. You need a photo to start off with and then you trace the photo using the corresponding colors. For me, every color I use has its own layer. It is important that the drawing layers are above the photo layer. You can also use a finger to select the correct color to use.
In addition, once you draw a shape, you can outline it very clearly with closed solid lines and then you can drag the color palette to fill the shape. It is incredibly important that the shape has closed lines or it will fill the entire layer.
I have seen many other examples of digital art, and they have a solid background. However, I like drawing certain parts of the background so that the picture has some more context.