Preparing for birth after a previous Cesarean for lack of engagement


Here are some recommendations for a pregnancy after a previous labor finished via Cesarean due to lack of engagement (baby's head had remained high and didn't come into the pelvis):
The classical suggestion of long, steady, almost brisk, walks still has much benefit. For some women walking daily is not enough. But realize, to walk well, wear flat, comfortable shoes, swing from the thigh and hold your neck long with the crown of your head to the sky, shoulders back and, of course, no tucking the bum. 
Visit for pregnancy focused tips on posture, walking, standing, squatting. Its a treasure trove! You will understand more after visiting Katy Bowman online.
Use Smart Maternal Positioning. See Rest Smart on Spinning Babies.
Please look at the Chiropractor/Myofascial Release/Craniosacral therapist and even Maya Massage bits on
Chiropractic techniques may also be done by some Osteopaths. In some areas of the world, you might find an Osteopath for the same purposes. 
These helpers will help you obtain maximum pelvic stability and Balance
If you have migraines, tight jaw or grinding teeth and other things effecting your neck and head, have a body worker and use self care for those areas, too, to help your pelvis "open". It may have been open, I can't say, of course, but an open, balanced pelvic alignment is the goal.
Achieving full balance and flexibility, helps you eliminate a potential tightness or twist effecting the brim of your pelvis (and everything else). Continually refreshing your balance with daily activities and regular professional body work helps make the most open, balanced pelvis you can achieve. 
Do the Daily Do's and Weekly Activities, too, according to safety for you (if you don't have contraindications for some, such as high blood pressure or placental bleeding). 
This way you can eliminate the question of whether your babies didn't engage because of something you could have done something about, or due to a pelvis that is actually "too small", in your case, at the brim. 
With Contractions, using the Abdominal Lift and Tuck for ten contractions first, and if that doesn't engage baby, then Walcher's Open The Brim technique. Do those with your midwife/doctor present because it is possible that once baby engages, if labor is already active, that birth could be rather soon afterwards, although it usually just gets things back on track for whatever stage of labor you were in when you did them, early or late labor. 
Moving freely in these ways and eating lots of fresh veggies, with lots of greens and drinking fresh, pure water (no bubbles and avoid toxic plastic bottles, please) are ways of improving your chances. 
The benefits of laboring are worth the challenge of finding the providers and making the arrangements to be supported for laboring. Whether you labor and push your baby out or whether you labor and have another cesarean, labor helps prepare both baby and mama for brain and blood chemical changes for the next stages of their lives.  
My hope is that you are supported and validated in your wise choices and you listen to your body and your baby without ideology, fear, or exclusion of choices. Only you can be present with what you need, now, and at the time of birth.