Clematis: Clematis in shrubs, 1 by Pfg

Pfg wrote:
I've read that to have a clematis clamber up through a shrub it should be planted 12" from the shrub root ball. But on which side?! Is the north side too dark? South side too hot? East? West? I realize that the vines will grow toward the south, which will place the flowers perfectly to be seen from the house. But where should the roots be?

I love Clem's, but there are already so many features in the main area that to add trellises or obelisks seems too much. I think there are plenty of opportunities to use them creatively, but of course want to get it right.

Thanks for any and all suggestions.

Pam