Axis locking

Hey guys. I need small help. When I try to extrude my faces, it’s always locked to some axis. How can I extrude something like on this video?
[video]https://youtu.be/iZM1ebow2cE?t=3m58s[/video]
Pressing E and then just moving faces across the space is what I want to do.

When you press ‘E’ faces often go along their normals.Just press “X”,“Y” or “Z” after pressing “E”.Or press middle mouse button to extrude where you like…

By default faces extrude along the face normals

Pressing an axis key (E X) constrains to the global axes or pressing the axis key twice (E X X) constrains to the objects local axis