1.    Domain name: Domain name is a very important factor of SEO. Therefore, to select a domain name we should to be careful so that it becomes relevant with the subject matter of the page.
2.    Title tag:Title of a page usually represents the content of the whole page in a phrase. So during the selection of the title one should be careful about the keyword, subject matter of the site. The title tag should be in the head tag in html code.
3.     Description Meta tag: It is also a very important html tag. In a quotation mark the summary of a site, have to describe in short. For getting a good result, the description should be rich of the keyword related to the site.
4.    Keyword meta tag: Some effective keyword, related to the subject matter of the site should be selected. Because the repetitive use of these words will be helpful for making the site important to the search engine.
5.    Use of search engine friendly URL: The URL is an important fact for SEO. Information rich heavy weight easy word should be selected as URL so that the user as well as the search engine can easily find it out.
6.    Use of site map: Site map is very important for SEO. As it makes easier to browse a site, search engine rank it up. Site map may make personally by coding or by site map-making site. The xml file can upload to the home folder by FTP software.
7.    Content management: Use of developed content is very important. Because use of good keyword may take a site at top rank but if the content would not rich then it can’t able to hold its position. So the content of a site should be rich of information of users requirements.
8.    Use of alter tag in image: Some times for different cause a page can’t load its contained image. Then the place of the images remains blank. But if we use the image alter tag  and write some effective words about the image, or the subject of the page then it will be important to the search engine. So it is consider as one of the important technique of SEO.
9.    Use of title attribute in link: If we use title attribute in a link, then when a browser take the mouse pointer in the link, a little description of the link will come out which is provided as tool tip. This work may be effective for SEO as the search engine gives it priority.
10.           Use of Robot.txt properly: Proper use of robot.txt will help the search engine to index a site easily. So it should use properly for SEO.
11.           Internal link building: Internal link build up is a very important technique for SEO. Because it makes easier to browse a site. Page jumps, page-to-page links are of this type, which is treated as back links.
12.           Do and No follow link: It should be careful about the using of do follow and no follow link. Because no follow link both have merits and demerits. It protects the spammers unwanted commenting which is a good side but it also protects normal commenting which is harmful for site communication.
13.           Marketing:  The ultimate work of SEO is marketing the a site by different social network, bookmark site, article submission site etc. are called marketing.