Here's a short tip on how to use the capture windows as a temporary visual placeholder.

With no command active, left click once and pull your cursor to the left to show the green crossing window border, but don't pick the second corner point.  Tap the ALT key to freeze the window.  The green rectangle will stay in position so that you can move the cursor around and point to other objects or menu items. 

I use this method in presentations all the time as a visual focus on geometry and still have the cursor as a pointing device for smaller details.  Best of all, the grips don't show up.  You can also pull to the right, after the first pick, if you want a blue rectangle instead of green.