Laghu vajrasana: To get down is somehow always possible. The challenge is to come up from this pose.
My new insight is, that it is easier to come up when I press the hips forward and not upward.
I practice the pose twice (more often would be even better, to build strength):
1. First I arch back till the head is on the floor and I stay in that position for 5 breaths. Once I am in that pose for a while, there is no way to come up.
2. When I practice this pose a second time, I arch back as far as possible with an exhale, with the next inhaling I come up. I use my hands as support. I engage my leg muscles as much as possible. The head is the last to come up.