The description meta tag plays major role on Google page ranking. don't forget Google own more than 60% percent of search engine traffic.Traditionally we are used to adding meta tag to blogger site similar to below by editing the html code of the blog.
<meta content='your site Title is here' name='title'/>
<meta content='your site keyword is here' name='keyword'/>
But what happen if you do the same for description tag ?? If you do that, every page of your blog has same description and search engine refuse to index those page by considering they have same content.so I'm going to discuss best practices of creating meta description to your blog.
* Adding Global meta description
1) Write a blog/web description
Take your time and create best description that is suitable to your site. it should be clear and concise with characters of 80 - 100.2) Login to blogger site
so let's take advantage of blogger inbuilt tool of putting meta description.go to Setting --> Search preference --> edit Description and save. Use blow screen capture for your reference
* Adding meta description for each post
3) So now you have successfully added global description to your blog. next thing is, put a description to each blog post.It's so simple. go to Post --> click "edit" which post you want to add description
find "Search Description" field from left hand side panel, insert you page description, now you are done.
Tip:- your page description should be the summary of the post. Remeber to add as much as keyword when you writing that summary ( to find relevant keywords use Google Adwords tool)
you can verify each meta tags including description meta tag using below tool.
http://www.submitexpress.com/analyzer/
4) happy blogging :)