My favorite posture for lengthening the psoas is moving slowly in and out of a lunge with the back knee down with your breath Kristi . I think that little gem is in the asana practice for the back body in season 2. I also observe in some people that the psoas isn't so much "tight" but holding on to a great deal of tension. Deep relaxation and Yoga Nidra work wonders to help reset the Nervous System. I'm sure there are a lot of awesome practices like that on this site. (I have one in another series called Body Poetry) Thank you so much for practicing with me!