How can I find out why Android Build and Run failing?

I have my device (galaxy tab II) connected, drivers installed, sdk set up, usb debugging enabled. I can build an apk just fine and then transfer that to the device to install, but when I try "Build and Run" from the build settings, nothing happens. No error message, nothing, the progress bar just fills up and then disappears. What could the problem here be, and how can I find out?