I know what you mean
I generally just go with faceswaps/general mucking about in ps when I have no ideas.

don't end up posting most of because it's so shite but there you go :)
(Slartibartfast. Is currently ignoring: Slartibartfast, Thu 16 Aug 2007, 14:41, archived)

Headswaps...
haven't tried one of those yet
(Pavlov'sDog is all out of pavlova, Thu 16 Aug 2007, 14:42, archived)

all you need is a picture with two people looking in the same general direction
and the clone tool really

:)
(Slartibartfast. Is currently ignoring: Slartibartfast, Thu 16 Aug 2007, 14:49, archived)