In terms of dreaming, have you tried the herb called mugwort? I've used it to induce intense and vivid dreams and I know that it's also been used to help a lucid dreaming state. Usually used in a spray for aromatherapy or in a tea. I've also used it for "dreaming pillows", I have a personal one made with jasmine, catnip, peppermint, mugwort, and a few other things. Many of these also help lucid dreaming.
I've also heard eating certain foods before bed affect the nature of your dreams, but I haven't really tried this myself.
In terms of thought exercises and whatnot, I try to stretch out the in-between phase of sleep, where one is getting to dreams but hasn't quite lost all their lucidity. It helps to try and force myself to bed before I'm ready, staying still and trying to imagine slowly dying and losing consciousness. In that, I try to seek out the "place" I want to go, desperately and needfully, and often by the time I've fully fallen into dreams I'm at the place I wanted to be. This may not have worked for others, but most of the ways to become aware while asleep haven't worked for me either, such as looking in a mirror to find your reflection, reading a book, checking the time, etc.
Good luck anon!
This thread is kind of dead, but I had this very same problem until about 2 months ago, so I want to help anyone else who might run into dry periods like this. For nearly two years I hadn't dreamed at all (or at least hadn't recalled any dreams). I was depressed as hell and tried a number of different approaches, but I found the thing that helped the most to get dreaming again was taking a whole bunch of melatonin (like 6X the dose) about 20 minutes before bed. Melatonin is a natural hormone that promotes sleep, it's well known to be harmless, and it's almost impossible to overdose on it. It's said to help induce vivid dreams (probably because it just makes you sleep easier), and the best part is, it's not prescription, so you can get as much as you want.
I've also found that I really don't dream much at all unless I get at least a good 7 hours of restful sleep, so make sure you're not going full med-student mode with your sleep schedule. Oh, and whenever you can, avoid using an alarm clock. It'll shatter your ability to recall anything once you've woken up.