Originally Posted by JSWolf
As for formatting, what is your preferred way to format an eBook so it looks good on most devices be they a smartphone all the way to a computer with a high resolution screen (1600x1200 or larger).
Do you mean what settings?
I use unjustified as the default, but many devices (Kindle, esp.) will justify the text, as I don't force the ragged right.
Margins set in Calibre to 9 pt., which I recently increased from the default of 5, because I think it looks nicer on more devices.
.25" indent, no spaces between paragraphs.
Widow and orphan control turned off, via a few CSS lines I add in Calibre.
Font color set to Auto rather than black, so it doesn't interfere with night setting.
Vertical spacing (such as for chapter headers) controlled primarily by spacing settings in paragraph styles, rather than blank lines.
Because I sometimes need weird indentations because of the crazy way I've formatted text in some books, I use nonbreaking spaces to push text right where I have to (on rare occasions), even though everyone says you shouldn't. It works great.
I don't have a smartphone to test on, so the only test I have for that is the Kindle Previewer, set to Kindle on iphone. Among various family members, I have a Kindle Touch, an ipad, a Nook Color, a Galaxy Tab 10.1, and a Sony reader to do "live" testing on.
One point of frustration is that block indent doesn't work in the Kindle format, so I've started avoiding it in new work.