You can change the name of the takeoff, the color of the takeoff, count symbol (if a count type takeoff), or add an Item or Assembly to a takeoff. Click on the three dots on your takeoff template, and then click "Edit". (You can also click on the measurement you have drawn to accomplish this)
You can then change the name, description, fill color, count symbol, or add an Item or Assembly. You can duplicate the the takeoff if you simply need to make slight adjustments to create another takeoff. You can also + add a takeoff to your library if it is one you frequently use to save you time.
NOTE: The only thing you are not able to change when editing a takeoff is the measurement type (i.e., you cannot change from Area to Surface Area).