Give *GOOD* suggestions. Do not suggest garbage in an attempt to get points. Also, the reason staff members and older users post the most is because they're able to give definitive answers to questions people have. Points don't really mean anything other than how much you've contributed, so you shouldn't really be concerned with gaining them if you can't contribute to a certain part of the site.
As a side note, I think people get way too many points for posting on the namechange/story threads, and while that is technically a good way to get points, I wouldn't say that you should do that just to get points. Points are supposed to gauge how much you've contributed to the site, and points you get from posting on those threads aren't really because you're contributing to the site... that's just my personal opinion, though.