Using Silo's Split Tool.

Silo's Split Tool is a simple and powerful way to quickly cut faces and edges into your model to add detail.  Note that there are other methods for doing these sorts of operations (e.g. the Connect command and the Split Face Loop command), but this tutorial focuses on the Split Tool.

You activate the split tool by selecting a single object and choosing Modify > Split Tool.  As with all other commands in Silo, this can be assigned to an image button, a keyboard shortcut, or a mouse click.  Once activated, your mouse cursor will change to indicate that the Split Tool is active.

One way to start your split is to click on an edge of the object and drag the point along until it is where you want it.  If you want to split a polygon from one vertex to another, click on the edge adjacent to the vertex and then drag to slide the created vertex to the end of the edge so that it merges with the vertex already there. In the image below, we're splitting from the middle of one edge of the polygon to a vertex on the other side of the polygon.

You can also add points along the split path as you go by clicking in the middle of the polygon you're splitting.  Dragging will move the vertex along the surface of the face.  You can add as many extra points as you like.  Finish your split by adding another point to an edge of the original face, sliding it to an adjacent vertex if you want.

If you start your split by clicking in the middle of a face rather than on an edge, you can draw out a polygon that will be embedded in the face.  Press Enter or right-click to finish the operation.

You can right-click or press Enter to finish one split and start another.  If you right-click twice or press Enter twice, you'll exit the Split Tool.  Pressing Esc will also exit the tool.