The Global FlyFisher
Simply the Best Place to go for Online Fly Fishing and Fly Tyinghttp://globalflyfisher.com/fish-better-patterns/trout-beads
Trout beads aren't beads in the traditional fly tying sense but perfect imitations of salmon eggs and deadly efficient for rainbows. And they can be fished on a fly rod.
Here is how to utilize the same method on a fly leader using a thing-a-ma-bobber. In this particular setup the bead is used as an attractor to a stone fly, however, if you're brave enough to go against the conventions of fly fishing, you could also use just a bead and a bare nymph hook (We won't tell anyone).
The bead is pegged to the line using a toothpick.
Clip both ends of the toothpick once the bead is pegged and slide the bead approximately 1-2 inches from the hook or fly.
Beads come in four sizes: 6mm, 8mm, 10mm and 12mm. Choose the size and color of your bead based on the size of your quarry, as well as the size, and clarity, of the water your fishing. For smaller steelhead, like those found in creeks, where water is often gin clear, start at a 6mm bead preferably in natural colors. For salmon and steelhead on bigger rivers, or in high, or muddy water conditions, you would be better off using a 10 or 12mm bead in buoyant colors like hot pink, chartreuse or even green apple!
Beads work, and are a far superior egg imitation than the "Glo-bugs" and "Sucker Spawns" of the world, by leaps and bounds. Whether or not they can penetrate the fly fishing kingdom of acceptance is another story. With no actual tying involved, and the only material being the bead itself (and the toothpick if you want to count that toward craftiness), the bead may have an even harder time than the San Juan Worm, when it comes to being accepted by fly anglers.