Knowing where to put keywords and how many should be inserted into a particular page is SEO 101. Despite this, many people are still in the dark as to how to use them for maximum effect.
I don't have a lot to do with SEO, because I believe good writing should incorporate a keyword and relevant synonyms anyway, without having to go ham on other SEO strategies. The location of keywords on a page, however, is just as important as the keywords you choose to utilise.
In order to find out the best place to position a keyword, I'm using a test undertaken by Page Optimizer and breaking it down for you. They created pages with keywords in 12 different locations then monitored how Google ranked them. They then determined whether placing keywords in the H1, H2, H3 or H4, meta title, meta description, meta keyword, body (2% density), as a bold or italic word or as an image alt was better.
The meta title, URL, H1 and body copy were the top weighted elements for on page keyword placement. Out of these, the meta title was the most important factor in helping Google recognise the relevance of a site. This means that it is important for meta titles to be unique to each page and include a keyword.
H2, H3, H4 and anchor text were next in line in terms of importance when it comes to Google's ability to identify your page. What I also found here was that Google brushed aside the meta description to focus on what it deemed as being more pertinent, such as the meta title, H1 and H2 elements. If you're wondering what this means for you, it's essentially a tip to use a H1 and H2 that are similar if you want your website to rank.
Bold and italic words also performed well, although I wouldn't recommend that you litter your page with these elements, since the're both secondary factors in determining the relevance of your page and these secondary factors tend to shift around. For those who are militant about adding alt text to a page, you may be surprised to learn that it ranked last as a weighted on page factor.
Schema, HTML tags and open graph were other elements found to be unimportant to Google's search algorithm, while meta description and meta keywords weren't even indexed.