One of these, suggested by John Novak in How to Meditate, is to simply lie down either on the floor or on your bed without a pillow and learn to breathe. You learn to control your breathing by just breathing in for a certain count, say ten or twelve, then holding your breath for that length of time (or double that length of time, depending on how you'd like to do it) and then letting it out for that length. You have to be careful to base your breathing counting on ticks of a clock or your heartbeats or a very steady sense of rhythm, because otherwise you may end up speeding up when you are running out of air or space in your lungs to keep inhaling. When you breathe in, you envision yourself filling up with light and energy. As you hold it in, you look at the insides of your eyelids and watch what is painted there. And as you let the air out, let yourself cool down. Do this repetition many times, as many as you like. While you're holding your air, you may feel a little lightheaded, as if you're drifting upward. This was always somewhat neat for me and my first real experience with consciousness shifting. I learned to feel something unusual when I was reaching out in the dark. It was strange but beautiful and sometimes I would feel as if there were other people out there welcoming me.
Another one I know of is very similar, but as you breathe in and out you envision that you are floating on the sea, and that as you breathe in the waves are taking you up and as you breathe out the waves are taking you down. There is no breath holding in this exercise. You must actually *feel* the waves as you breathe; keep taking in air until you really feel that the water has lifted you up, and keep exhaling until you feel the wave has passed. Do not worry about if you are sinking or that anyone is with you. You may feel as if you are being lifted up above the ocean; if that happens, just let yourself drift up sometime to see what it feels like. It is a very calming, stress-relieving exercise if you need it, and a thought-provoking and joyful experience as well. (Also from Mr. Novak's book.)
Here's one from Starhawk's book The Spiral Dance, a very important and empowering meditation called the Tree of Life. For this, sit or stand erect and imagine your spine as a tree trunk. From the base of your spine, roots go down into the earth, reaching down until they strike a power spot in the earth. From here, with every breath, you can draw the energy into yourself, slowly up the roots, until it flows up your spine. Every breath you take makes you feel more alive. Out of the crown of your head come branches that sweep downward to touch the earth; the energy comes up the back of your neck and bursts out into the branches, traveling down toward the earth. Make sure that as it does this you can feel the movement of the energy. Guide it to slip back into the earth, and just let it move through you. When you are ready to end, allow the power in your branches to come back up and into your head, down your neck and down your spine, trickling out of your roots and into the earth. Now you can relax.
Here's an interesting thing to meditate on. Choose a dream you've had recently or an older but memorable one. Get comfortable, center yourself, and try to call up the feelings and images you had in the dream, while awake. See if you can attain a lucid dreaming type state, and try to figure out the meanings behind people and things in the dream by asking them what they mean. If you are able to remember a dream well enough to do this, you may be able to gain some insight as to why you had that dream.
There is a practice called "pathworking" that I know almost nothing about and have had little experience with, but it is a kind of meditation where you go on journeys in your mind, and visualize the places you go. Most of the time you really feel you are there; it is more than imagination. You might see a painting, then close your eyes and imagine journeying into that painting. You might take a guided trip from a tape or an instructor, going on a journey focused on the spoken words. You might even awaken from a dream and then consciously continue it, controlling it.