When my son was small, he struggled with sleep. The slightest noise became a roar, a sliver of light a spotlight. We had a well-established, not-to-be-deviated from bedtime routine and a well-respected bedtime, and even with all the "t's" crossed and "i's" dotted per the sleep specialists, he still struggled...until we discovered the magic sleeping lotion.
I wish that I could claim the genius of discovery, but I owe that to my mom. On a visit to my parents, my son once again struggled to fall asleep. My mom walked softly into his room, whispering "do you want to try Jakey's magic sleeping lotion?" (Jake was my nephew, a few years older and was idolized by my son.) My mom rubbed the gentle baby menthol-scented lotion onto his chest, explaining, "this puts Jake to sleep right away!"
He was out like a light.
Normally, I despair of habits like this. What if they stopped making the lotion? (They did, by the way.) What if I ran out on a night he needed it?
I quickly realized that the scent was the trigger. Sure, it purely psychosomatic - there was no real trick here, and we didn't even disguise the lotion bottle with a special label - but it worked. Soon I began to introduce other scents, chosen from my drawer of essential oils, and labeled them as "sleep aids" and "anxiety aids". Whether you find them "woo woo" or believe that they do assist in sleep, anxiety and other complaints isn't the issue here - the point is that if your children believe they do, they will, and that's all that matters.
After all, isn't there a particular scent that brings you back to a moment it time at first smell? Scent is a powerful sense and is one that is closely linked to memory. Once my kids associates a scent with a much needed super power, I found that it didn't take much to soothe them at night. While they no longer need the spray, if test anxiety or the like has their brain spinning, a little essential oil in the diffuser is enough to trigger that feeling of calm and control.
So if you have a little one, get a clear plastic spray bottle. Fill it with water and a few drops of an essential oil that you and your child like. Label it "magic sleeping spray" or "monster spray" or "nightmare spray", give the room a few pumps of magic and see if it calms your kiddo. Likewise, you can find a gentle scented lotion (no need to make your own if you don't want) and reserve its use for sleepless nights.
You might be surprised.