I have dim memories of the 1968 and 1972 elections.
But, my first vivid memory of an election happened in the summer of 1973 when I lived in Athens with friends. Greece was still governed by a junta of military leaders. They were trying to create an air of legitimacy for their regime, and so they decided to hold a referendum on a new constitution.
The day before the voting, three truck loads of armed guards, complete with machine guns, arrived at the polling place in the school across the street from our apartment. The ballots to vote in favor of the referendum were marked "Nai" or "Yes" in bright blue, the national color of Greece. The "Oxi" or "No" ballots were in a dingy grey. The voters selected a ballot and put it into a translucent envelope and if you selected the grey "Oxi" ballot, your name was taken down.
This was not how we had voted in my hometown in Connecticut which was, and is still, governed by an annual town meeting.