Have been tying a few of these up this week. A few, more like about 5 dozen.
I fish small nymphs a lot and using a leader with a strike indicator built into it. I find these much more effective as I believe most of what trout eat is pretty small. I went back to my notes that I took some years ago when I was knocking fish on the head to eat but to also see what they were eating (I don't kill fish anymore). Here is some of the data. A bit dated and generalised but it does show that food can be very small.


So here is what I use:

1. Iron Blue



Hook: Partridge IN Size 20
Bead: Black Tungsten
Weight: 3 turns of fine lead wire right behind the bead
Tail: Microfibbets - splayed
Body: Two parts. Rear is Hends Body Quill No BQ08 (Crimson) Front is Hends Body Quill No BQ15 (Grey)
Wing Bud: CDC tied short
Thorax: Natural Mole

2. Little Olive (Pale Watery)



Hook: Partridge IN Size 20
Bead: Black Tungsten
Weight: 3 turns of fine lead wire right behind the bead
Tail: Microfibbets - splayed
Body: Two parts. Rear is Hends Body Quill No BQ93 (Yellow) Front is Hends Body Quill No BQ20 (Light OLive)
Wing Bud: CDC tied short
Thorax: Hare Poll

3. Olive



Hook: Partridge IN Size 18
Bead: Black Tungsten
Weight: 4 turns of fine lead wire right behind the bead
Tail: Microfibbets - splayed
Body: Hends Body Quill BQ39 (Mid Olive)
Collar: 2 turns of CDC placed in thread
Wing Bud: Crystal Flash (Yellow)
Thorax: Hares Ear

Hope you enjoy