The quest to become a responsible catch-and-release fisherman starts with the kind of tackle you use. There are two ways to attract a fish. One is with bait, and the other is with a lure.
Bait can be anything from a worm to a can of sweet corn. Lures come in all shapes and sizes, but they usually look like a small fish and have multiple hooks. Some bass lures don't look like fish, but simulate attractive movement with shiny spinning metal spoons. Bait is more likely to cause a gill or stomach hook, which is bad.
Treble hooks, which have three prongs, are more likely to puncture and wound the fish as well. Many lures come with treble hooks, but you can replace them with single hooks. They even get through the water easier that way. Fly fishermen use tiny artificial flies made by hand that have similarly low mortality rates.
There two basic types of single-pronged hook -- J-hooks and circle hooks. J-hooks look like a letter 'J.' Circle hooks have a similar shape, but the bottom of the 'J' is typically wider, and the point comes around more toward the stem instead of straight up. Using circle hooks is less likely to result in deep hooking. For each, you also have the option for tiny metal barbs along the metal. Barbed hooks are tougher to get from a fish's mouth.
You can speed up the time it takes to remove a hook by only using barbless hooks or crimping the barbs with some pliers. It's also important to buy hooks that are appropriately sized for the fish you're trying to catch. If the hook is too large it can do more damage. A strong line also helps to get the fish in quickly.
So you've got your barbless circle hook, and you're using a lure instead of bait. The fish hits your line, and it's time to land it. Bring the fish in quickly and efficiently using a steady and deliberate technique. You should never pull the fish from the water using the line. You need to man up and do it with your hands or a net. If you use a net, use one made of knotless cotton mesh or rubber that's less likely to harm the slime layer. Some fishermen don't advocate the use of a net at all.