I like to get as much text on the screen as possible, so I use top and bottom margins of 0, and left and right as 10 (0 here means the text is too close to the edge of the screen).
I don't like books that have the title/author/chapter etc at the top/bottom of each page - this wastes space and if I don't know what I'm reading then I'm not paying attention.
I also use a base font of 8 points. This is readable in good light up close when using the small zoom. In less ideal conditions I simply use the medium zoom, which is similar to a base font of 10 points with small zoom.
If I use 10 point as the base font, then there is no way to make it smaller when the reading conditions are good.
I now re-format all books I buy/download to use 8 points as the base, and I would be grateful if more people did - if it is too small for you, simply zoom in! But if you give me a 10 point book, I can't make it any smaller without having to edit the book myself.
