[rjwse@aol.com]

I have been using the editor in calibre exclusively for many years for original writing. That is to say, I do not use any kind of word processor at all. To create the necessary code is trivial: just wrap each paragraph in <p> and </p>. Add <h1> and </h1> around the single line tile. At this point you are done. More complicated things you can learn as you go. Actually adding these tags is via calibre also: the snippet feature can pop in these tags quickly without fuss. My snippet for the P tag is pp followed by ctrl-j. Later, you can learn to modify the tags internally by adding style ("s, ctrl-j" = "style=""). Many people disdain collections of styles called "class" but I like them very much ("c, ctrl-j" = "class="") My classes are like "tac" = "text-align:center", "df" = "display:flex", "aic" = "align-items: center". Over the years all this has become automatic <ol>, <li>, "bia" = "break-inside-avoid", "jcse" = "justify-content:space-evenly". Depending on if the book has lots of images with top, bottom, side captions and so forth this method creates absolute precision of placement for size, left or right, etc. The epub is finished completely in calbre's editor. You can open it in with "v" in calibre's main screen to read it as an epub with the built in viewer. While in the viewer you can click "c" to convert it into PDF for sending to amazon for printing. Calibre does not have its own PDF viewer but you can set a keypress from calbre's main screen to open a PDF to read it that way after conversion. I have ctrl-e for evince and ctrl-o for okular. You really don't need two. Yes, to be fair, you can spend months and even years to teach yourself how to enhance via tags. But it takes the same amount of time and effort to learn how to use all the details of an ultracomplex word processor. The conversion process from word processor file to epub is sometimes not precise and it is very hard to tweak. I do not recommend my method for everyone; it is personal.