I find an indent of 1.2em to work best.
Code:
body {
margin-top: 0;
margin-bottom: 0;
margin-left: 0;
margin-right: 0;
text-indent: 1.2em;
orphans: 0;
widows: 0
}
p {
margin-top: 0;
margin-bottom: 0;
margin-left: 0;
margin-right: 0;
text-indent: 1.2em
}
.spacebreak {
margin-top: 2em;
text-indent: 0
}
Code:
<p>This is a paragraph with a 1.2em indent.</p>
<p>This is another paragraph with a 1.2 em indent. Notice no line space between.<p>
<p class="spacebreak">This is a paragraph with no indent and a 2em section break.</p>
That is very clean, works very well and looks good.