Ashtanga we know righ,t but perhaps a closer look at what I mean by a 'simple' and 'core' VK practice is called for.
There seem to be recommendations and suggestions (I'm taking recommendations as stronger here).
Following his teacher Krishnamacharya, Ramaswami recommends practicing daily
He also suggests
I tend to throw in a chanted Sury namaskara as well as a short Asymmetric subroutine
Put both the recommendations and suggestions and my additions together and you have my Simple core Vinyasa krama practice
Vinyasa Krama is a naturally flexible approach
I tend to do a basic ten minute tadasana routine but there are several other options within the full On your feet 'tadasana' sequence. You may wish, as I did earlier in the week, to substitute in a few more twisting movements or squats.
I tend to rotate daily the Asymmetric subroutine, one day maha mudra, another, the marichi or half lotus subroutine. Find them all the options here.
I tend to stay in straight paschimottanasana and work on my breath and bandhas but there are some options while in the pose.
Backbend counterpose options are here
Following Ramaswami's advice I keep the first shoulderstand simple, relaxed legs for the first three minutes, just working on breath and bandhas but for the second Shoulderstand there are all kinds of options (the link includes the shoulderstand prep). I tend to do standard ashtanga finishing, halasana etc out of habit.
Headstands too have many options ( the headstand comes up at 3:45 )
I manage to keep the practice down to an hour, nothing feels rushed, overall it has a highly meditative feel to it. For me, my morning asana practice is preparation for extended pranayama and meditation but, of course, if that's not your bag, you can add in another half hour of Subroutines, some Triangle or On one leg subroutines perhaps to bring it up to a 90 minute practice in line with a standard Ashtanga practice.