We use balsamic vinegar (or wine) to lure fruit flies. I make a trap with paper, scissors, tape, a glass, and vinegar. Get a clean glass and fil it with a few cm of vinegar. From the paper cut a funnel with a small hole (2 mm or so) on the bottom. Use the tape to attach the paper to the glass (use more tape if there are open holes cause else they might escape). The paper will slowly get spots from the flies/liquid. Lasts a couple of weeks. Be careful when you toss it away, so that no flies escape.

We zap flies with an electronic zapper (looks like a tennis racket). There's a couple of tricks I learned from it but yeah just make sure you clean up the mess. The zapper resides on the fridge because we got a young human being frolicking around.