When I first started this blog, I just took the template that I liked and adjusted the colors to suit my style. Now after a few months I realized that I would really prefer to have 3 columns, but how to change it took a lot of research and reading. I forgot to take a screenshot, so now that I have created a test blog I set it up with the 2 col template again and some test entries and took a screenshot for reference.
I tried yesterday to make the changes and it would just not work, so I switched back to the 2 column style. Then last evening I came across another site with instructions. I realized that the problem the first time around had to do with my initial template I used. I had started with the 'Minima lefty' template and following the new instructions I had found I had no problem converting to 3 columns. The only thing I had to change was the code for the original left column, to make it the right column.
Taking screenshot of the 3 column layout straight after conversion will remind me how it was once I have made some changes.
Now my next step is to fine tune the look of my blog. At Blogger Buster I came a cross a PDF ebook with instructions on how to make changes to the template, I just haven't had the time yet to read it all.