You are already on good path. Search engine optimization is the only way to increase SERPs worldwide. If you wants to rank your website higher on various search engines in us than you need to work in .com domain or all that website hosted in US. You can use any of SEO techniques to increase SERPs. I would like to recommend one website for do-follow social bookmarking list(directorycritic), article directories and also for directory submission.
Blog posting, Blog comments and Forums discussion is also good techniques to improve your rankings.