Good design, Title tag, meta descriptions, heading 1, header title in space bar, alt tag(image), footer links, in home page 300 words content put, site map, robots.txt, in any page also put inbound links put.
Looks like you guys already know the best on-page optimization strategies. Just to ass to the bunch, adding an external link to a site with industry authority is helpful as well.
Do not upload too heavy data or images plus videos on your website as it may cause slow downloading of it. Get Webmaster tools for proper indexing. Write good ans short titles and their meaningful descriptions. Also make internal hyperlinks on the keywords related to your site. Prepare a HTML sitemap for visitors and XML sitemap of search engines. Write unique content for your website. The design of your website should be user friendly.