I have been talking about self-promoting crap that Google stuffs into Blogger blogs by default. Now I will show you how to get rid of it. After completing advice in this post, you will have a clean blog that's all your own while still using Blogger infrastructure to host it.
Contrary to other free blog hosting services, Blogger allows you to use your own domain (2nd or 3rd level) without paying a cent to Google. You just need to pay about $10 a year for your domain purchased from some nice registrar like Namecheap. And since you can have as many subdomains on your domain as you wish at no extra cost, you can use the same domain for all your blogs and websites. So go, buy a domain ASAP before people start linking to the Blogger subdomain your blog is using now. Integrating the domain into your blog is a matter of tweaking some setting in Blogger and in control panel of your registrar.
Blogger toolbar can be turned off under Layout menu. It jumped back on me once, so perhaps I will definitely remove it from the HTML template using the techniques below. It doesn't do anything useful for your blog, so no need to look for replacement.
About me widget in the sidebar can be removed under Layout menu. You definitely want some about me info in the sidebar, but it can be added later using for example the custom HTML/CSS widget, which allows you to fully customize the text and layout of the about info and most importantly allows you to put in there links to your own web properties instead of Google's default links.
All the following techniques require editing HTML under Template menu. The HTML is huge and messy. CSS is inlined in the HTML and consequently on every page of your post. I will probably have to find some time to completely replace the HTML with some simple template that is sufficient to run my blog. Presently I just show you how to hack the original HTML to kill Google' self-promotion crap.
Footer attribution must be unlocked in HTML and subsequently removed in Layout. This is messy and I have eventually ended up commenting the whole thing out in the HTML code. I have commented out the whole footer tag and it did the trick.
I've completely disabled post footer (not the same thing as page footer) by commenting out divs with class "post-footer". Blogger allows you to customize it, but no amount of customization made it look good enough. Either the layout is broken or some Google crap is left in. I just removed it completely. Sharing buttons are a nonsense anyway, serving mostly as a free advertising for social networks, but if you insist on including them, you can stuff your own sharing buttons into the HTML template. Including author's name is pointless if the blog has only one author. All that needs to be left under posts is the comment form.
The blog has to be tested on mobile to check that the mobile version has been updated as well. I think it is required to select "Custom" layout for the mobile version for HTML edits to have any effect. Better yet, disable the mobile version entirely. Tablets have large enough screens to view the full version of the blog. Smartphones have text reflow feature that keeps the blog readable on small screens. You will save yourself from the trouble of maintaining two versions of your layout.
Instead of using Google's image hosting, which involves links back to Google in all its forms, you should host images yourself. This is somewhat tricky, because you need to buy file hosting services. Nobody will give you such service for free unless you agree to use their domain, which just shifts the linking problem elsewhere. I run a $5/mo VPS to host some of my other stuff. Since I already have it, it's pretty easy to setup an FTP server that allows me to upload images to one of the subdomains on my domain at no extra cost. I can then just paste the link in Blogger image import tool. Blogger does some nice image resizing, which is not available when using links to 3rd party servers. I have to resize the images before uploading them. That's easy and quick to do with any image editing program.
Now that the blog is clean of Google's stuff, we can populate it with our own widgets by using the generic HTML/JS widget. I don't recommend any of the standard widgets except maybe Google search. Search used to be broken sometimes, so perhaps you should avoid that one too. More advanced customizations require hacking the HTML template or the inlined CSS. No big deal if you are technically skilled.