How much sleep are you getting? I know I'm a bit less likely to have particularly interesting dreams if I'm incredibly tired/stressed or if I'm only getting a small amount of sleep.
I'd also try thinking about previous dreams where you did the dreamscaping while trying to get to sleep. Prime the mind more for similar things.
You could always try calea zacatechichi, if you live in the states.
Try getting a little buzzed on alcohol before you go to sleep. That always makes me remember more dreams.>>1888
I've had friends have some success with this. In the US you can buy it on the Internet. It's a powdered herb, sometimes in pills, that makes you dream more and sometimes lucidly. It seems to work better if taken several nights in a row.