One of my favorite books I read when I was a kid was a book called Cheaper by the Dozen, which had tales about the life of Frank and Lillian Gilbreth and their 12 children. (Actually, the book has been made and remade into movies, which I didn't see.) In any case, the parents were "efficiency experts." Back in the 1920s, the concept of working efficiently was a new idea, and the Gilbreths came up with numerous breakthroughs in industrial engineering and motion study. Since reading the book, avoiding wasted actions and saving time has interested me.
With computers, one trick can make you more efficient immediately: using templates. Most people have some passing glimmer of understanding about Microsoft Word templates, but in general, a template is useful for anything that will be repeated. For example, you might need to create a letter multiple times, so you save your logo and return address into a template.
The concept of templates can be used for more than letters though. For example, I edit articles for a magazine. Each one has to be formatted a certain way. So I saved the layout into a template. Sure, it's a really "plain-Jane" template, but even having that dead-simple layout stored into a template saves me a little reformatting time on each article. A little time saved here and there can add up to a lot of time in the long run.
You can take the concept of templates out of the word processing realm as well. In fact, you don't need to use software that has built in template features to use the template concept. For example, suppose you've carefully coded a nice layout for a Web page in HTML. For navigation purposes and site continuity, most pages on a site should look similar. So you can save the overall layout and navigation into a separate HTML file. That's your template. Instead of starting from scratch, when you create a new page, you just grab your HTML "template," save it as a new page, and add your page-specific content. (A little word to the wise: do the Save As on the template before adding your new text, so you don't accidentally overwrite the template.)
Even graphics can benefit from the template concept. Suppose for example, you have a monthly report that includes five drawings that are all the same size. You can create your five correctly sized boxes in your favorite drawing program and maybe even include sample figure captions. Then save the file as your "template." Instead of starting with a blank page, you can open your template file, and start from there.
Any time you find yourself doing the same thing over and over again, consider whether you can save part of the file as a template. Efficiency comes from avoiding repeated motions, and using templates can help you get more done with less effort.