This is my technique:
I start by taking nice position, usually at my back (I sleep on left side always), let my hands and legs just go where is the best place. I set my pillow (always only one thin pillow, because it's hard for me to relax my neck otherwise) where is the best.
Now I take a deep breath and start to concentrate on my body parts one at the time, starting from toes, I concentrate on the big toe until I feel some tingling in it, the I move the tingling feeling towards to my ankle and so on until I reach my fingers. I move quite slowly making sure everything is relaxing.
Then I start to do the same thing, but I concentrate on my whole body at the same time. This stage doesn't take much time if I have done the first half well. Now I look to the black and feel my body rising upwards and flowing lightly.
This usually takes about 10 minutes and it's quite easy way to relax, I almost always get to the part where my body starts to flow.

So, what is your technique?