You can do the following:
1. On-Page Optimization - its a process of optimizing withing your site (like meta tags, title tags, headings, description, keywords, and alt-tags)
2. Off-Page Optimization - its a process of optimizing outside from your site. It actually deals with building links.. All of the strategies that generates back links fall under this type..

Most of all, is the CONTENT!.. In the end, what counts most is the quality of content. Visitors will be coming back and forth if your having quality content - fresh and interesting..

Before you do the on page optimization , list the set of keywords that you will be using for your promotion. Then the choosen keywords should be place on your meta tags, like on your title (which is very important), meta description and meta keywords.

yeah agree keyword research is the most important. select those that is not highly competitive enough.

Keyword research, relevant and unique content, generating backlinks, linking up with relevant sites. Some of basic and proven things you need to follow for better results.

First you have to choose the right keyword that fits on your site. Then that's the time you can do SEO. SEO or search engine optimization is a process of improving the volume and quality traffic of a website on search engines. There are two types you need to consider, first is On-Page Optimization then next is Off-Page. Both should go together.

add keyword like niche , bulid backlink , add tag ....

On-Page and Off-Page is the best thing to do. On-Page Optimization (meta tags, title tags, alt attributes, headings, keywords) first then next is Off-Page Optimization (article and directory submissions, blog commenting, forum posting, classified ads, press release, link exchange, online groups).