When you hold down Shift to get the Measure template (cone, square, circle, etc.) to persist, the natural course of action is to shift to the Select tool so that you can resolve the effects of the template--usually selecting tokens and applying Status effects or adjusting Hit Points or some such. Unfortunately, then you need to switch back to the Measure Tool to get rid of the persistent template (unless there is a shortcut that I don't know about), and then back to the Select tool to continue play. My suggestion is to enhance the persistent template such that you can dismiss it without going back to the Measure tool again. A "dismiss" button on the little black square that tells you the properties of the persistent template (who created it, size, etc) would be ideal I think, but perhaps a new hotkey would work too. I have found it quite annoying to switch back and forth between Measure and Select just to dismiss the template. Maybe that's just me?