Lower the amount of line on your spool. It will resist the energy of the bait being launched less, which means more energy stays in the lure.

Make sure your line guide is centered, if it's on the left or right, it will increase friction and hurt your max distance.

Make sure when you cast, you point your rod at the lure or the floating line, again this is a friction thing.

Up the strength of your action if you're throwing 3/4 or greater. Most combo rods are medium action and not suited for that weight or greater. In fact, if you throw a 2 ounce, you might just snap a medium action rod.

Get a longer rod is another easy way to increase your distance.

Have more line out for your cast. Some pro fishers have as much as 4 feet of mainline dangling behind them before they launch the cast.