As best I recall, at our precinct no one marked anything on the ballot before they handed it to me. After I marked my votes, I put it into the machine with the poll worker watching to make sure there wasn’t a problem with it and it registered correctly. If there was a problem and it didn’t register correctly, I assume they may have then taken action to mark the ballot or correct the problem… but not before I put it into the machine. Seems like that would be a good system. ?