How can astrology help my friend maintain a Yoga Nidra routine?

A friend of mine has begun the practice of Yoga Nidra, and I can see how it might be helpful for him. But I also see that a steady practice can be difficult to keep up at times. I'd love to know if astrology can provide insight into how to help him maintain a regular routine so he may get the most from the practice and become more grounded and balanced.