If you get a ship leader with a trait related to exploration put them on the survey ship, it will help increase the odds of finding ruins and IIRC will increase the odds of finding something valuable in the ruins. I tend to leave ruins alone until I get a survey ship with an appropriate leader at the helm, unless the AI is close enough to be a threat in pillaging the site.
Remote exploration might identify a ruin, but if not send the survey ship to sectors where remote exploration did not yield a ruin. You also learn more about the planets in a system with a survey ship.
You also want to have a combat ship with the survey ship as it helps the survey ship escape encounters with space monsters.