Google tells you a lot about what you need to do already, check out your traffic stats.
If traffic from search is concentrated to a select few pages, and not many others rank in the top 10, make sure those are the pages you actually want traffic to. If they are, look for other pages you may want traffic to and concentrate incoming and internal links to these pages. A noindex meta tag on the others might not be a bad idea either if they get no traffic.
Remember: pages with noindex meta tags still count towards your link profile. Rank flow, trust, pagerank etc all count on these pages and pass on to links from these pages, they just don't show up in search.(don't confuse a noindex meta tag with a robots.txt exclusion)