Meta tags and general on-site SEO (minus keywords) account for like 5% of your total SEO score. The vast majority will be in selecting your keywords, using them, and BACKLINKS!
Backlinks make or break your SEO. They account for your Google PageRank, Authority, SERPs, and more. All that is what really matters, therefore backlinks are your main focus.
To get backlinks, you can have really, really, exceptionally good content and SEO'ing that people find by itself... or use SEnuke and cut the time it takes to grow your site by SO much!
you can get a copy here