Fishing streamers in spring often produces the biggest trouts of the season.

But fishing can be difficult under the high water conditions after snowmelt and you need a pattern that dives easily and draws some attention with a strong motion and some flash/glitter.
This pattern immitates a common minnow (Phoxinus phoxinus) which is one of the most important prey species for European brown trout, but also for perch, asp and chub. It could also serve as a trout fry immitation.

The streamer has a weighted front with one or two beads according to the situation, and an air filled rear end which floats up. The air is trapped in the mylar tubing, which has been sealed with epoxy. The streamer therefore makes a nice head-banging, or zigzagging motion under water, which strongly attracts trout and many other predator species.
The mylar adds some scale-like, flashing reflections and the orange sheen of the egg yarn draws further attention.

You can also vary the colors and weights as desired. I also tie a white version with a completely hollow belly (no dubbing there) and a pink tungsten bead in the front.