I achieved a First in Psychology during my first year.
I would say a key factor that contributed was my lack of friends/social anxiety. In lab classes we would often be required to work in groups to learn about statistical tests, when to apply them and how to conduct them using a program. When a lot of people did this sort of group work, it would be one (maybe two) people doing the work while the rest of them nattered and didn't pay attention. However, since I sucked so badly around people I almost always ended up on my own and therefore I had to learn how to do everything by myself. Ultimately this meant that in this module's assignments and tests I achieved well above average. Er, I wouldn't recommend this as a strategy though, at least the 'not-having-friends' part.
For exams I prepared about a month in advance and it was basically just rewriting notes on small cards and rehearsing over them. This year (second year) I also added in writing question prompts on the topics I had gone over and answering these prompts out-loud, as well as simply talking about the topics I had gone through with my family. I don't have my results yet, but I felt fairly confident during the majority of my exams so hopefully it worked out.
The final piece of advice I would give is to not aim for just 40%. So many people in first year had the attitude of 'eh I only need 40% to pass so I'll just aim for that so let's get smashed lol'- that's not a good attitude! That sort of mentality should only really be used as a means of calming you down if you're feeling really stressed and genuinely worried about progressing, at least in my opinion.