Rabbi Pesach Krohn speaks about this on a shiur dedicated to this;
some of the points he mentioned were;
1) invite a Single into your home in the week, not just on Shabbos.
2) if you invite a girl and boy for a Shidduch, let the girl help you, she may tell you things about the boy in the kitchen she would be embarrassed to say at the table.
I forgot what else he said, you can hear the Shiur if you like.