Android Programming is a lot about efficiency to have snappy user interfaces. The Android SDK provides two nice tools to help building efficient UI’s. In the tools directory you find the tools:
layoutopt is a command line tool which can analyse a layout resource file and tell you what is not required and hierarchyviewer is a tool to view the View hierarchy of your running application.
I suggest to have a look at these tools and check your layouts especially if you have created a complex application.