During my first instrument training flight (at about 8 hours TT or something) before we started my instructor told me to close my eyes and then through a combination of slow undetectable roll/pitch changes and normal maneuvering had my inner ear convinced we were rolled left/nose low until I opened my eyes and saw we were rolled right/nose high.
Takes all of 1 minute and is teaches you very quickly how easily your senses can become disorientated.