When throwing a fluke I will rig it weightless on a 4 ewg hook. The hooks I use are cheap bass pro hooks. I sometimes wait to set the hook if they are just bumping it. You can generally feel when they inhale the bait. I will set the hook pretty hard and fairly quickly when I get a bite, as long as I think they inhaled it. Also, make sure you reel the slack out of your line before you set the hook. I have a good hook up ratio doing this.
Sometimes I miss a couple of bites in a row and when I look at the fluke it will be balled up around the hook. When this happens I will take it off and put a new one on or adjust the way it was hooked.