How to change size of maximised window?
 

Is there any way to change the size and shape windows take when they are maximised? I figure there must be, as taskbars do this automatically. I want to stop windows covering the XFCE4 panel. Thanks.

Go to the preferences widget thing and define the 'border' that apps can't cross, IIRC. I think that's what you want.

Great thanks - for anyone elses reference, you open the settings program from the XFCE4 panel (or run xfce-setting-show) and then change the Workspace Margins. My panel was 42 pixels high.