I need to trim down my RSS feed so that people come back to the site to read the full article, how might I do this and is there a preferred / best method?
That's what Teasers are for — the Teaser is the shortened version of the content, presented in RSS feeds (among other places, such as the site's front page).
When editing a node in Drupal 6, use the "Split summary at cursor" button to split the node's body into a Summary/"Teaser" and "Full view".
Then go to your site's
/admin/content/rss-publishing page, and set "Feed content" to "Title plus teaser".
Additionally, on your site's
/admin/content/node-settings page, you can configure the default length to use to split nodes.
Try Display Suite / Node Displays, gives you a nice interface for themeing the output of different displays (Full node, Teaser, etc) including the RSS output, so you can move the fields around, use Custom Formatters to theme them, and add extra fields as required.
Nice easy way to customize your RSS feed as you need.
Plus the settings can be exported as a Feature.