This kind happens to me too, except frequently when I'm transitioning I see a really bright like that comes from "above" (hard to describe which direction) and it wakes me back up because it's intensity. Though no one I talk to seems to know what I'm talking about. But the vividness before becoming unconscious (or the white light) is often the most creative part of my day. Sometimes I can take control but often this breaks the effect.
Though the best way I learned to remember dreams and having some control is not when falling asleep but waking up. Rather set an alarm one or two REM cycles before you want to get up (cycle is 90 minutes) and then just go back to bed. It's far more vivid than when trying to go to sleep and easier to take some control (though I've only become lucid twice). At minimum you'll remember your dream.
Some buddhist sleep meditations are often called clear light meditations.
For them btw is not the trick to remember the thoughts but to stay aware when transitioning to the sleep phase, this is one of the moments clear conciousness can be experienced according to certain teachings.
Though the best way I learned to remember dreams and having some control is not when falling asleep but waking up. Rather set an alarm one or two REM cycles before you want to get up (cycle is 90 minutes) and then just go back to bed. It's far more vivid than when trying to go to sleep and easier to take some control (though I've only become lucid twice). At minimum you'll remember your dream.