Now that the weather has turned cold again, trout have gone deeper in the water again seeking comfort and food. Nymphs are a great source of food for trout during the Winter and Spring months. Nymphs are immature insects that start life underwater and then emerge to the surface when reaching maturity.
When fishing with artificial flies, the trick is to make them look as real and natural as possible. When fly fishing, casting your nymph upstream and letting it sink as it rides the current downstream helps. Letting the fly rest on the bottom and rise to the top gives the appearance of a natural nymph emerging to the surface.
The video below demonstrates this technique.
Here's another great video - demonstrating the use strike indicators and fishing a double nymph rig.
You don't have to be a fly fisher to fish with nymphs. Many spin fishers fish with nymphs too! If you're nymphing with a spinning rod, you'll want to use a float. There's a great article on spin fishing with nymphs that shows you how to rig your pole and offers fly selection advice and more.
If you're having trouble catching trout, try fishing with nymphs!