For the general population here is a nice modified shoulderstand and inversion supported by blocks and only if there is enough shoulder mobility would they do the versions without the blocks.
The blanket is added to give extra space for the neck. It should be wide enough that the shoulders and upper arms have room to be on the blanket. This is an individual thing since the should width varies. Start in supported bridge, roll shoulders under, press upper arms into the blanket, lift legs, hold for a few minutes – optional bind on the bridge holding onto ankles then lifting hips before coming down to floor.
