Advantages of New Blogger templates compared with old classic Blogger templatesPublishing a post is much faster. New Blogger templates uses dynamic pages versus static pages for old classic template. New Blogger templates have drag and drop LAYOUT with which you can easily customize your blog without having to get into the actual template and wade through long list of codes and perhaps not knowing where to place some codes for some customization or hack. You can easily add and move Page Elements (widgets) like New Blogger Link List (blogroll) or Label List, advertisements, etc. Below is a screenshot of a New Blogger LAYOUT:
If you want to add something, just click "Add a Page Element" and select from a list of various Page Elements. If you want to move something, just hover your mouse over the Page Element you want to move, the normal "white arrow" mouse cursor will change to a "cross arrows mouse cursor" (highlighted by a pointing red arrow in the screenshot of the LAYOUT above), and all you need to do is to right-click on the mouse, drag and drop the Page Element to wherever you want it, click "Save" at the top right of the LAYOUT. No need to edit the template. No need to know anything about HTML, CSS, widget codes, etc.
And Google Blogger is increasing the number of list of Page Elements with time plus other third party developers are adding more widgets (same as Page Elements) for you to use. I will publish another post regarding the advantages later as this post is about how to migrate from old classic Blogger template to New Blogger template. If you are worried about losing your customizations, I will write about it later.
How to upgrade blog using old classic template to New Blogger templateGo to blogger.com, sign in to Dashboard, click TEMPLATE for the blog you want to upgrade to New Blogger template. This will take you to the template editor. The very first thing you should do is to backup your template. Click on the inside of the template editor window, right-click and choose "Select All" (or press ctrl+A) to highlight the whole template, right-click again and select "copy" (or press ctrl+C) open a Notepad file, paste the old classic template into the Notepad file by right-clicking and choosing "paste" (or press ctrl+V), save it in a suitable folder with a descriptive file name, including as much details as possible, possibly including the name of the blog plus the date, etc. Make full use of the ability of Windows to use long file names. This will save whatever customization you may have done and help you put them back into the New Blogger template plus give you the chance to get back to your old template if you changed your mind. Actually this may be a superfluous step if you just want to revert to the old classic template as Blogger save it for you, but if you choose to continue with the New Blogger template, this backup template can easily help you extract various customizations you have like visitor counter, advertisements, etc., if you can recognize them.
Next step - at the top, you will see some tabs and sub-tabs:
Click the "Customize design" sub-tab, then click UPGRADE YOUR TEMPLATE. You will then see a list of New Blogger templates. If you can decide on one, fine. If not, choose anyone and don't worry. You can always change later. Click "SAVE TEMPLATE". Don't worry. You can easily change later.
Sources of New Blogger templatesIf there is no standard Blogger templates you like, there are third party New Blogger templates at FAQ: 3 column New Blogger templates.
If you want to know why I use this template for all my main blogs, surf over to Best template for my blogs. Template choices are obviously a very personal thing, so you may not agree with me. However, you are free to choose from the templates tested and demonstrated in FAQ: 3 column New Blogger templates and more will be added as I have the time to add them.