An often overlooked step in getting rigged and ready to fish is straightening the leader. Most Trout leaders consist mainly of butt material with a short taper and tippet. The butt material is the stiffest portion of the leader and it holds the most memory. Whether we pull a fresh leader out of a package or pull it off the reel the leader is stored in a coil which causes the material to "remember" its coiled shape. Leaving the coil works against us in several ways. First, a leader with a memory problem is more difficult to cast in that it is less aerodynamic. Second, a coiled leader makes casting accurately very difficult because the coils don't unroll to a consistent length. Third, a coiled leader takes us out of contact with our flies. Whether fishing nymphs or wets on a floating line, sunk line lake tactics or pulling streamers, feeling a strike is paramount. A leader with too much memory reduces contact with flies, decreasing strike detection.
There are several products available for leader straightening. Naturally they are called "leader straighteners". Most fly shops carry at least one leader straightening product. If not, do what I do and use your hands. You can easily remove memory from most leaders by running the leader through your hand, warming it slightly with friction and then giving it a good stretch.
Here are a few online options to purchase a leader straightener:
Take an extra second or two to work the memory out of your leader. The fish won't thank you for it....