I would suggest them to not hold eye contact for too long, but do not avoid it. A short eye contact in every 10-15 seconds would be fine. As for punctuality, he/she should have the ability to express themselves here, not overly punctual, but he/she should be understandable. As for humour, we like to laugh and fool around, but he/she should pay attention to not be rude or overly sarcastic.
