1. Write a description for the blog.
Go to the Settings tab and in the "Basic" option you will find the text field in which you can put the description. This is useful for newcomers and it might be helpful for search engines too.
Dashboard → Settings → Basic
2. Get a nice template.
There are many websites with Blogger Templates (as a matter of fact this is one) in which you can find a great variety of designs.
Do not base your decision only on the graphic side (headers, buttons, icons, etc) but also in the structure (number of columns, accessibility, etc) and remember always to read the instructions for each template because usually they are important in order to get the right visualization of it.
3. Buy a domain and use it with your blog.
I’ve always said that a domain has to be the blogger’s first investment and by less than 10 dollars you can have a proper name with a lot of advantages, this is heavily advisable. Have a look on adding your own domain on Blogger.
Dashboard → Settings → Publishing
4. Change your blog’s feed for a Feedburner one.
Feedburner is a Google service that allows you to have stats of how many people read you via this method. From the Blogger’s Control Panel it is possible to add feedburner to your blog.
Dashboard → Settings → Site Feed
Post-Feed-Redirect-URL
5. Correct the comment link.
A little detail that improves your blog’s accessibility. To correct the comment check it has to be done by hand.
6. Change the images of your template to a new host.
Many templates have their images hosted on free services which limit the traffic to them (bandwidth) which makes it possible to sometimes none of the images load properly. Hosting them on Blogger seems like the best option.
7. Add the basic gadgets on your sidebar.
In the "Layout" tab select "Page elements" it is possible to add gadgets. the most basic of them are: Labels, Blog Archive (list mode) and Subscription Links.
8. Embed the comment form in the entries’ individual page.
As this feature is still on test phase it is necessary to do it by hand in customized templates or automatically in Blogger’s default templates.
Dashboard → Settings → Comments
Comment-Form-Placement
9. Add your stats-tracking code.
It doesn’t matter if you use whether Google Analytics, SiteMeter or any other stats system, the important thing is to add their tracking code before the </body> that is in the "Layout" tab, "Edit HTML" option, almost at the end of the code.
Dashboard → Layout → Edit HTML
10. Add Google Tools to your blog.
The Google Tools allow you to keep track of your search stats and errors related to your site. Its use is really intuitive and free.
After doing all this your blog will be a more effective tool, you’ll have more control about your stats, it’ll look better, it will have better negotiations with the search engines but on top of that, it will be a better space for your visitors.