Fish on the Bottom
Use lead sinkers. Don't be shy about whipping out the heavy artillery. Lead sinkers will help drag your line to the bottom, where flounder normally lurk. Because flounder are ambush predators, this brings your bait directly in their range.
Find the Hot Spot
Give trolling a try. While keeping your boat in a spot by structures, a hot spot for flounder, use your lead sinkers and drop your line. Then put your rod in its holder and power your boat slightly. This way you're keeping the bait where the flounder usually stay, and you're not relying on wind or tide like you would with drifting.
Mark Your Hot Spot
Mark any hot spots you find. Where you find one nice-sized flounder, there's normally two or three more waiting to be caught. Once you pull up your first, use a marker buoy and drop it over the spot you found your catch. That way as you troll you won't wander too far from your hot spot.
Know the Right Time
Keep migration times in mind. Flounder migrate between September and November. It's during this time they move from the creeks and river beds into the ocean. Fishing during this time increases your chance of success.
Equipment, Bait Make a Difference
Have the right equipment. Use a medium stiff 7-foot casting rod; it's perfect for catching flounder. As far as bait is concerned, using finger mullet that's about 3 to 4 inches in length is ideal. If you use anything smaller, it won't fit on the hook. Anything larger, and you risk the flounder biting the bait but missing the hook. Mullet can be hard to find so if you can't get your hands on them, use mud minnows as a substitute.
Know the Strike Signs
Be sensitive for the strike. A flounder's strike is gentle and will never pull the rod from your hands. Sometimes it feels as a soft tug or pressure. Don't set the hook right away when you feel this. The flounder will often take the bait in his mouth but refuse to swallow until he's back in his safe spot. This can often be about 10 or more feet away. Let him pull a little, and then set your hook-- otherwise you'll have a shredded mullet and no flounder.
Find the Right Structure
Fish around the jetties and rocks. Flounder love underwater structures. This is the perfect area for them to lie in wait for their next meal. You'll have more success if you concentrate on these areas.