1. First of all you need a custom blogger template, there are many sites on internet provide you free custom blogger templates but btemplates.com is best among them. choose a blogger template that matches for your blog topic. you can preview the templates there it self. Download the template file which is a zip file. so extract it using winrar. A folder will be extraced. Open that folder you will see xml file. This is the file you need to upload to the blogger

2. Now open dashboard of your blogger account go to design menu and then to edit html
                         dashboard----design------edit HTML.


     now before uploading backup your current blog template so that if any thing went wrong you can came back to your orignal blog looks. now click on choose file and select the XML file in the extracted folder.
     After selecting the file click ok. now click on upload. after uploading you will get this:

       Now you can view your blog. If you are not satisfied with the looks. search for other good looking templates. Upload them. Never compromise Do the best You can.