It's not much, but it's helped the look of my site.  By applying a custom field to a specific blog post like so:

Your content (regardless of index, archive, or single placement) then renders like so:

<div class="MyCssClass">Actual Blog Post Here</div>

This allows each post to have different (but common) CSS Styles.  Other plugins allow you to apply a custom stylesheet per-post, but my plugin is more useful when there are a few common styles you want to re-used.  All that's missing is uploading the following code to your wp-content/plugins directory:

<?php

/**
 Plugin Name: Legion's Div Content Plugin
 Version: 0.1
 Description: Wraps the the_content with a custom css class specified in the "legioncss" custom field
 Author: legion
 Author URI: http://FeelingsOfWhite.com
 */

add_filter('the_content', 'legiondiv_the_content');

function legiondiv_the_content($content) {
    global $post;  //required to access $post->ID
    $customCssClass = get_post_meta($post->ID, "legioncss", true);
    if ($customCssClass != "")
        $content = '<div class="' . $customCssClass . '">' . "$content</div>";
    return $content;
}

?>

As a n00b to WordPress, it's hackability has impressed me.  I'm amazed that this is all it takes to write a plugin.  There are plenty of fantastic resources available just by searching the web.