Use the Window/Workspace/Reset "Your Chosen" Workspace to default values Menu Or simply double click the current workspace in the toolbar and choose Yes. This workspace is about as fouled up as I can make it and it's reset in a couple of seconds.
You should also expand the workspaces in the tool bar and edit the ones that are visible in the tool bar by just dragging them around. Workspaces are a fabulous time saver. This is how mine are setup.
The expressions workspace is a custom workspace I created and saved just for writing expressions.