We explored the shape of supta padangustasana in many ways this week and even tried NOT using the strap.
Virasana
Adho mukha svanasana
Supta Padangustasana 1, 2, 3 (with strap, without strap)
uttihita padangustasana (with strap, without strap)
parsva uttihita padangustasana (with strap, without strap)
Vrksasana
Ardha Chandrasana
Sirsasana (or prasarita padotanasana)
Salamba Sarvangasana (or vipariti karani)
Marichyasana 1, 3
Savasana