Recently I am playing with the Google 3D to see whether we can find some good slopes for northerly wind. It is really cool as we can set any view direction to see the 3D images. I highly recommend you to try before attemping to go hiking searching for a decend slope.
Here are some cool images:
Clearwater Bay, both east and north slopes
Fei Ngo Shan east slope
Fei Ngo Shan north slope
Fei Ngo Shan south slope
Ma On Shan east slope
You can even see the car park and the hiking track up to the mountain
Shek O from different angle
Sham Chung, you can see 村長間屋
Lamma Island from a different angle
I have searched a few possible northerly slopes and hope to go there sometimes check them out. Cheers!