A Sea Change

I had hoped for a more enigmatic image today, but ended up with an easy-to-read 'scape of the mist-shrouded Heads. Earlier I'd tried out some double exposures to get me in the mood for a run of wildly mysterious shots I envisage taking. Only I have no idea how to go about them (the wildly mysterious shots)! I want to do it all in-camera, just to be difficult... images that are part blur, part sharp, swirly, confusing, with hints and scraps of identifiable things in them. At the lagoon's edge I progressed to taking out of focus shots, which looked great in miniature but hurt my eyes when I viewed them up large.
I need all the suggestions I can get : ideas, tips, good sites to go to... please indulge me. Long exposures? Pinhole camera? Image overlays?