Some comments on modifications to my journal style, for my own reference mostly.
I do 95% of my customizable LJ reading on the friends page, so the goal was to get it as skimmable as possible.
The style currently in use is here: http://www.livejournal.com/customize/advanced/layersource.bml?id=7945668&fmt=html.
I've made the following changes from the version 
rilina sent me:
- In S1, the date only displayed when it changed; in S2, it has to be displayed on every post if at all. My S1 style had the date in red, but in S2 that was too much date information, overwhelming more important stuff. So I moved the subject line to the top in red, and set up the CSS so the subject line, the poster (if on the friends page), and the number of comments are on a vertical line.
- Removed color and underlining from links to tags in individual posts, because they were distracting.
- De-bolded "mood" and "music" for the same reason.
- Added conditional display of "(no subject)".
- Made display of "add a comment" conditional on there being no comments. ETA: further modified because original code broke the layout when a post's comments were disabled.
- Modified the skiplinks (previous, next) so that they were bracketed as a unit, not individually. Left-justified them to the main column since they can't be centered across the whole page.
- ETA: sidebar edits: added link to website; modified style of active location.
- Used "replace_text" to turn line breaks in auto-formatted entries into paragraph tags, and then indented the first lines of paragraphs (except in blockquotes). It's not perfect, but I think it looks better the vast majority of the time.
- ETA: show poster name when viewing community pages in my style.
Comments or suggestions (especially how I can get the read-comments link to go to #comments, as I could in S2 managed, thanks to ckd) are welcomed. Thanks again to rilina.