Mention which is the most important area to include your keywords?
 

Mention which is the most important area to include your keywords?

What do you mean by area, Vineeta?
If you are talking about the place within an article, then it's always good to have the keyword at least once in the first paragraph of the post.

We can put keywords in title tag, description tag, keywords tag, h1 tag and in alt tag.

In heading first,second,third and density should be 2 % of total words in the article

H1,H2 Tags
Title
Meta Descriptions
Meta Keywords
Content
Image Alt tags

In terms of creating a strong SEO, put your keywords in title, meta tags , h1 tag, anchor text and content and keep a keyword density of 2% of the total words in the article ,even though 2.5% is allowed but it is always preffered to take 2%. I have a jewellery website, normally i work on these platforms

Title tag
URL
Content of page
Image alt text
Meta tags
H1,H2 Tags
Meta Descriptions
Alt text
Anchor text etc.