This tip will work in AutoCAD 2013 and later versions only.
The PressPull command can be applied on bounded regions and surfaces, and it always tends to make a normal feature with respect to the base feature. For example, if you apply the PressPull command on the top surface of a cube, it will add/remove mass along the direction normal to the plane.
Here is the example of what the PressPull command will do if applied on top face of this geometry (indicated in red)
To use the PressPull on tapered geometries so that the direction remains same as the direction of the geometry, you can use this method.
Select PressPull command.
Press and hold Ctrl key on keyboard.
Click on top surface.
Leave Ctrl key and enter height either dynamically or with the keyboard. You will notice the PressPull command will follow the tapered direction of the geometry.
The result should look like this:
Notes from Cadalyst tip review R.K. McSwain: Many commands in AutoCAD can be modified with the Ctrl key. This is a good example of one such case.