Originally Posted by starrigger
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.
That actually sounds pretty good and would be a good enough format for most people.
As for avoiding blockquotes, I suggest you don't. Don't cripple the ePub because of a flaw in an obsolete format.
Oh and one thing that would work very well and quite easily is to use margins set to 0 in your CSS and a simple @page to set the 9pt margin that you want. That would make it easy for people to change the margins without having to find all the places you've set the margins.
If you would like some testing of your eBooks on an iPhone using iBooks and Bluefire reader, I'd be happy to help. I have an iPhone 3G and will be upgrading it when I can to the new iPhone (4s was a dud (IMHO)).