Melatonin has worked wonders for me as well. However it's worth mentioning that the 3mg capsules I bought are WAAAY too strong and cause me to wake up with a dry mouth and a headache after a couple of hours of intense dreaming and nightmares. Instead now I split the caps open and take a tiny fraction of the melatonin every night. It takes me a few weeks to go through a single capsule.
Interesting, I take 3 or 6 mg per night about an hour before sleep, I've never experienced that but it does make my dreams more vivid and memorable and I wake up from the occasional nightmare as well.
Interesting how different doses affect different people differently.
Melatonin works great for me as well. I take 5mg. Not sure if my dreams are any more vivid than without it, as I've been taking it every night for years. I think I've always had vivid dreams, though I no longer get recurring nightmares (which I had years prior to taking melatonin; not sure when they ended).
I split the 3mg sublingual tabs into quarters. I often split them again and take part when I go to bed and the other part after reading and getting a bit drowsy. Seems to do some good (N=1 and all that).
I definitely think that if you're taking them under the tongue the doses they sell them in are much too high. Probably make more sense if you're swallowing them.