So, from time to time I'll find myself in a dream, stuck in a fearful state...
For example, stuck up super high at the top of a building, unable to climb down, paralysed by fear.
A while back, I realised that this kind of terror doesn't ever take place in my waking life, so it could potentially be used as a trigger mechanism in the dreamstate.
So that's what's been happening lately.
I'll find myself stuck, then my rational mind recognises the un-natural state it's having to try to navigate, and full lucidity kicks in.

A couple of nights ago I took this to a new level, when, stuck up at the top of a church steeple, I not only gained full lucidity, but turned the entire dream landscape into a giant multi-coloured spinning vortex, which I promptly dived down into...
hurtling through and into a whole new astral landscape.