When you’re planning a wedding, don’t forget your single friends. Even though you may extend the invitation to them and a guest, often they are still going to come alone.
(Let’s face it, unless you are pretty involved with someone, there is no faster way to scare them off than to invite them to a wedding where they might get “ideas”.)
So when setting up your seating arrangements, keep your single friends in mind. Don’t put one or two singles at a table full of couples (unless you know they are all part of the same social group/friends). By the same token, don’t put all the single women at one table and all the single men at another.
Consider doing away with assigned seating altogether. Most couples have a few tables reserved for bride’s and groom’s families as well as the wedding party, and then the rest is open seating.
If you feel you must have assigned seating, then try to keep it light and mixed gender. Focus more on your wedding and less on playing matchmaker.