I love OS customization. Don't you? Ever since OS X Mavericks debuted, I've been complaining about the nearly solid dock. Finally, I stumbled across a system setting that enabled me to restore my dock to its pre-Mavericks more-translucent look.
As with many tweaks, the solution depended on a Unix command-line directive to the defaults (that's Mac for "settings") system. You enter this at the Terminal (/Applications/Utilities/Terminal), specifically:
defaults write com.apple.dock hide-mirror -bool true
After updating the defaults database, you need to restart the Dock:
The screenshots on the right of this post show the results. Using the normal settings, you can barely see through the dock at all. Once you apply the mirror hiding override, the dock becomes far more translucent, enabling you to see more of the desktop below it.