I can´t see any sense in white VS black hat discussions -
some white hat seo technique could turn out to be black hat later, example.
reciprocal link building, in early seo times was absolutely white hat. It is not anymore.
White hat SEO is anything that is in Google's official list of how to optimize your website. Read google's official blog :)
white hat techniques are the way of link building according to the algorithm of search engine whether it is about on page of page tactics.
Most popular techniques of white hat seo is link building.
Quality Content and get Quality Inbound Links is the best white hat seo techniques.
Link building and quality and fresh content are some of the good techniques of white hat SEO.
Link building is the most popular technique in white hat seo.
Article submission which relevant to your site and commenting on blog which also relevant to your site are including in white hat seo.
may be white hat SEO link building like bookmarking..
link sharing is a best technique.
Most popular Technique of White Hat SEO is social bookmarking.