Ramaswami has Sarvangasana (shoulderstand0 along with Sirsasana (headstand) and paschimottanasana (seated posterior stretch) as the three postures his teacher, Krishnamacharya recommended practicing every day and for a considerable length time.
Sarvangasana, it is suggested, should be practiced for anything between five and twenty minutes daily.
Ramaswami recommended we spend three minutes in Sarvangasana with the legs relaxed then another two minutes with them straight in classic sarvangasana. After that first five minutes we might then consider exploring some of the vinyasas.
Looking ahead I think we have seven sarvangasana subroutines.
Ramaswami would also recommend a counterpose after sarvangasana so as to relieve the strain placed on the neck and shoulders, he suggests bhujangasana (cobra, Day 45) and especially makrasana (crocodile, Day 44) as ideal counterposes, stating that, 'The counterposes, as a rule, should be simple, effective and targeted' (Yoga beneath the surface p105).
The above practice sheet shows the advanced lead in, it requires a degree of flexibility in the neck and shoulders at picture 8 that may not be available to you.
It is important that in Picture 8 the shoulders are on the mat rather than the back of the neck, engage jalandhara bandha ( the chin lock)
Rather than risk strain in the early stages one may consider the alternative approach below.
Here a blanket is used beneath the shoulders, creating space for the neck and avoiding any strain.