The best way to get reputation marks is to make intelligent, well thought out posts and topics. Rather than making simple one-sentence answers, flesh them out with more reasons as to why you think a certain way, or use more examples. Don't get discouraged when people don't give reputation for quality posts though. I've often had posts I was very proud of not get reputation or even answers, and others I thought were mediocre get high marks. It's a bit of an odd pick-n-choose as to what people like.
Also, don't just make longer posts with the idea of getting reputation. If they are redundant to other people's posts, or just repetative of what you've already stated in the post, then it will come off as if you are padding your posts. Posting to every single thread isn't a good way either. It can be considered spamming.
It does take more than just having high reputation marks to become a moderator though, but it's probably a good start to get noticed around the community more.
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