Hello Chromatic, and welcome aboard to Line of Action, and I'm Polyvios Animations and how are you? Say, where can I see your latest drawings and sketches and paintings, so that you can document where you're shooting off from? Good night, and have the greatest thanksgiving.
Forshorting is very simple. It effects everything we see unless you are standing back with a telephoto lense and it happen when an object moves back in space.if you have 2 parallel lines moving back in space, if you draw an X between the front and back of the shape you will find the center of it. This displays forshortening. There are more complicated ways to explore it. You can learn more about this from drawabox.com.
Perspective can even effect cross countour lines around a figure. If you can learn to identify them. You can add clothing or add things to the envirment that match the perspective.
You can teach yourself to see forshortening intuitively with drills, I will make a post in my sketchbook just give me a minute.
It really explains well how you should think about foreshortening and perspective.
Another thing that helped me is I took a model using an online model poser and started drawing it from a pose that I was comfortable with (not foreshortened).
After I roughly drew the pose (no need for a detalied drawing, you just need to get the hang of the volume of the major shapes, drawing with boxes is also fine) I started moving the camera a little to make the model seem more foreshortened (Just a little bit), now I draw the model from the new angle.
Continue moving the camera into a more foreshortened angle each time until you've reached the maximum level of foreshortening.
If you've reached the level you want, congrats - you now can draw foreshortening!