Figure 3.10 - Contextual menu for extrudes
Keep in mind that using the contextual menu is only possible right after
you finish the extrude. It works the same way as with object creation. If
you start another operation in Blender, you will no longer be able to
change settings using that menu.
Tip: The Toolbar options are also available in a floating menu that you
can call using the SHIFT+SPACEBAR keys.
3.3 Loop cut
The Loop cut tool is another useful option to change the shape of an
existing object in Blender. Unlike the extrude tool, you won't create new
geometry with the Loop cut. Instead, you add new edges to an existing
model—the edges loop around your models' shape to give you more
options in modeling.