I have to define paragraphs as indented, because otherwise I cannot properly see when paragraphs should not be indented (because it's actually a continuation of the same paragraph after a poetry fragment, for instance), or when there is a scene break.
But I still hope some reader will allow the user to override the default styling for <p> (or any other tag), so I keep my styles as simple and self-explaining as possible. In particular, I use just
<p> instead of
<p class="normal_text"> or
<p class="style1">