I passed first time, but to be honest that doesn't mean much, since I have no idea whether I passed by half a mark or by 20 marks (such is the transparency of the profession).
Personally, I found that the two most helpful things to do when studying for CA1 were:
1. Learn the acronyms. There are questions in the exam which are just basically asking you to regurgitate core reading, and you really want to pick the marks up on these. I went into the exam with about 60 acronyms in my head, and I used quite a few of them to pick up easy marks. If you are able to read a 4 or 5 mark question and immediately recall the points to get the marks, it means you can spend more of your time on the more "thinky" questions.
Also, don't just blindly use the ActEd acronyms. There will be some stuff that you can remember easily, so there's no point in spending time learning an acronym for it. Likewise, there might be some things which are difficult for you to recall but which have no acronym, so make your own! You are much more likely to remember an acronym if you had to come up with it yourself.
2. Do the past papers. Nothing gets things into your head better than going through proper questions. My technique was to answer each question in the revision books and mark them as I went along. For every question where I didn't do very well, I highlighted it. Then at then end of all the questions I went back and did the highlighted ones again. I kept going over questions until I managed to get through everything without needing my highlighter.
There are lots of other things that people who were studying with me did, such as writing up their own notes, making mind-maps, etc, but these were my two favourite techniques. Really you just need to find out what works for you.