My Secret to FCPX Color Grading - Magic Bullets Mojo
Magic Bullets can be downloaded here: http://www.redgiantsoftware.com/products/all/mojo/
Red Giant is most well known for their full version of Magic Bullets that often plugins into major applications like Adobe Premiere or Adobe After Effects. Magic Bullets Mojo is a dialed down version of the application, giving you addition Final Cut Pro X Effects to add more in depth color grading to your video. While there isn't much wiggle room beyond the effects, you can adjust each color correction to your liking using a variety of sliders. At the price point of $49.99, I think this plugin is a must for any amateur/intermediate YouTuber, videographer or filmmaker using the latest version of Apple's Final Cut software!
Any questions are welcomed in the comments below. Thank you for watching/commenting/rating/subscribing! You guys rock!
Red Giant Software also make Trapcode Soundkeys; which is a great plug-in for working with audio and adjusting levels in your compositions. There is a great lesson on CreativeCow.net on how to work with Trapcode Soundkeys by Aharon Rabinowitz.
http://library.creativecow.net/articles/rabinowitz_aharon/waveform_1.php