Well, I'm not a portrait photog, so can only give a "general" suggestion.
Take a photo and do your best, then post a "Before" shot and then the shot that you have worked on, and post either a screen shot of your various adjustments or a detailed explanation of what you have done, tell us how you would like the photo improved, and see what kind of input you get!
And, if you upload your original to a site like YouSendIt.com and post a link here, people could download the file and mess with it and post their results!
If all you have to work with is Lightroom, make sure you specify that, otherwise people will come out with "photoshopped" results that may not help you!