Here is a tip that will allow you to reuse sketched geometry on a part, even if the sketch is consumed with an extrusion.
Create geometry with multiple shapes. In the example, we used a circle and a centered rectangle.
Extrude the circle. This will consume the sketch. (Make sure it is not adaptive.)
Right-click on the sketch consumed by the extrusion. Select Share Sketch. The sketch will be moved and copied in the browser and should be turned on. It will then be ready to be shared again.
Extrude the rectangle. (You may have to change the extrusion direction.) You will notice that Extrusion2 and Extrusion1 use Sketch1, the shared sketch.
Note: This Inventor tip has not been reviewed by a Cadalyst tip reviewer.