A very hard achievement to get to say the least, but here are some guides to get started:
(note I did not make either of these)
Here is a text guide for some of them which I found rather helpful :http://www.xbox360achievements.org/game/n-plus/guide/
But something that I am finding very helpful towards getting this is achievement is these video guides: http://www.youtube.com/view_play_list?p=7D85B5DC78B917AA&...
Sure you can just go look at the top ten on the leader boards, but they are the top ten for a reason mate. I know I didn't have the skill to follow them most of the time. I had a much easier time following these, because he only goes for gold when you need it, and he just goes for completing the levels, if there's a longer but easier way, he'll do that, unlike the leader boards.. (note: he's only up to 40 atm but coming along fast)
And then we come to basic tips:
- Take breaks, the more frustrated you get, the more likely you are to be reckless
- Gold is not mandatory, you don't always need to collect it, try and know when you do and when you don't.
- Read the level name sometimes it offers a hint on how to do the level.
- Take a look at the level before you start and try and work out how to do it.
Well that's it, Good luck - You'll need it!