When you are casting a fly line, there is a lot to keep track of–maintaining a straight path with the rod tip, stopping at the end of the front and back casts, accelerating smoothly through the casting stroke, etc.–so it’s easy to just forget about the line hand. But controlling the fly line in your hand during the cast is key to avoiding a couple problems, such as line wrapping around the butt or the blank, and to ensuring that you’re ready to set the hook as soon as possible after your fly lands. In this helpful video, George Daniel demonstrates how making an “O-ring” with your thumb and forefinger will help you maintain better line control and miss fewer strikes.
George Daniel operates Livin On The Fly, a guide service in State College, Pennsylvania. He is also an Orvis ambassador and the author of Strip-Set: Fly-Fishing Techniques, Tactics, & Patterns for Streamers, as well as Dynamic Nymphing.

Not what I said what I was expecting when I saw the title mentioned o-ring
Soft plastic lures are popular fishing tackle; and just like all other equipment, it’s your responsibility to properly maintain and dispose of them. Over the years, plastic lures have been improperly used and disposed of, consequently ending up on lake bottoms or in fish stomachs. Fish can ingest these lures off the bottom, and that can negatively impact their health. Soft plastic lures on the land or in the water also pose environmental concerns. There is no doubt, discarding soft plastic lures on land or in the water is littering and poses environmental concerns. Instead, dispose of used lures in a trash can or recycling canister. Several Maine boat launches offer bait recycling canisters, and many local fishing clubs and retailers also offer bait recycling programs. Essayservices[dot]org
Furthermore just don’t use soft plastics. Plastic is one of those inventions I would rather replace.