Take a piece of paper, use a pencil, fill in the bubbles next to photgraphs and names of the candidates and/or parties.
Modern systems should be able to handle checks, dots, etc...
Place a stack of cards in the voting booth and allow print a big sign which says "if you make a mistake, toss the card and start over on a new one. If this is too difficult, ask for assistance".
Allow a maximum of one card to be inserted into the machine per voter... I.E. the booth will have to be manually reset by an adminsitrator between voters.
Now we have resolved the problem. If using this system people still can't get their vote right, then we might be able to agree that they wouldn't get it right even if someone were to specifically interview them and do the work for them.
Best of all, there's a paper trail and there's electronic counting. The electronic counting can run real time as the votes are cast. Then at the end of the day, the cards can be automatically fed.. MULTIPLE TIMES into a counting machine to count, recount, and RE-RECOUNT every vote for final verification. There should be the EXACT SAME NUMBER of votes every count. If there isn't, then someone should be arrested for malicious tampering or stupidity.
When it's ALL OVER, after 10 years of physical storage and safeguarding, the paper can be recycled.