SMT reel: taking a couple of parts off the reel
It's better to "harvest" parts from the front of the reel, this way you won't mess with the tape that much. Leave all the excess cover tape in place, don't cut it off; otherwise the pnp operator would have to extend it somehow, usually by separating the tapes and throwing away 20-40 pieces of a part.

If the pnp machine is nearby you can also harvest parts after the tape has been installed in place, just ask the operator.