Foreshortening Practice

I feel that foreshortening is one of the weaker aspects of my comic drawing, which is a bit of a bummer when you consider that the best comic illustration is that which involves well executed foreshortening. Therefore I figured a bit of practice was in order. The above sketches are all taken from reference - the next step is seeing if I can commit it to memory and learn how to draw foreshortened anatomy off the cuff!