As a reminder, Ramaswami recommends we spend five minutes in Sarvangasana (first three minutes with the legs relaxed next two with the legs straight in standard Shoulderstand) before practising the sarvangasana vinyasas
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).
This Subroutine could follow on nicely from Day 68 : Supta ardha badha halasana to Halasana
For Halasana (pic 2) from Sarvangasana (shoulder stand) we first place our arms outstretched along the mat and then lower the legs to the mat above our head on the inhalation.
Lowering on the inhalation gives more control of the descent as does engaging the legs by stretching out through the legs from the hips to the feet.
Remember to lower and raise the legs from the hips rather than thinking about lowering the feet to the mat.
Uttana Mayurasana (stretched peacock )
From Sarvangasana tuck the tailbone, engage moola bandha by drawing up the anus, bend the knees, expand the chest, arch the back and lower your feet gently to the mat on the inhalation.
Lowering on the inhalation gives more control as does engaging the bandhas.
Stay for a breath and then stretch first one leg and then the other, press your feet, from the toes to the heels and both sides of each foot firmly into the mat.
Stay for three to six breaths lifting up through the hips as in dwipadapitam
Return to sarvangasana by bending the knees bringing the legs back to where you first landed them.
Support the back, exhale, hold the breath and raise your hips and thus your legs off the mat, the knees stay bent until you ar vertical again when you stretch the legs back up into sarvangasana.
Some may find the the uttana mayurasana vinyasa's, where the legs are lowered one at a time (pictures 4-7) easier or less intimidating than full uttana mayurasana, in which case, you might wish to switch them around in the subroutine, at least in the beginning.
This vinyasa is less intimidating because the trailing leg can act as a counter weight to the leg lowering to the mat behind you.
From shoulder stand lower one leg above your head (your right leg say) then inhale, hold the breath and bend the knee of the upright leg (your left) and arching your spine and supporting your back with your hands lower the left foot to the mat behind you.
As you lower your right leg will come up, stretching out through this leg will give control of the descent to the mat of the other leg. The right leg will come up to vertical as the left leg comes to rest on the mat behind you
Stay in this position with one leg bent and the other straight for three breaths. Stretch out through the vertical leg from the hip.
After three breaths on the next inhalation stretch out the left leg along the mat while trying to keep the vertical leg stretched and engaged.
Stay for another three breaths.
To return: On the exhalation bend the left leg again bringing it closer to the body, stay for a breath. Exhale, hold the breath, press down from the shoulders to the elbows, round the back and from the hip raise the leg allowing the right leg to lower back into eka pada halasana. On the next inhalation bring your right leg back up to join the left in Sarvangasana sthiti
Basically, as one leg goes down the other come up like a seesaw.