Thanks Paco and Akira
Akira,
The theory is the same I've been using for 2 years or so, I just have accumulated a bit more experience doing this sort of shooting, over the weekend I went to an island in the pacific (the same location I've been going for 5 yrs or so), this time I took more exposures than before, thankfully the sky cleared at night as it was mostly cloudy during the day, I was there for two nights and I have another couple of sessions to develop
Paco it takes a bit of stubbornness to accomplish some worth while results, I was there with a friend doing the same thing, so it helps to have some support as it can get frustrating to get the proper alignment and focus, the first night it took me a good 90 mins to get everything to my liking before letting the camera shooting the multiple images, second night the preparation was a quick 10 minutes.