Normally I'd use small flies for these, but this crankbait I found at Walmart is doing a fairly good job : r/MicroFishing

The world's smallest shrimp fly, Global FlyFisher

Fishing with MICRO CRANKBAITS!!! (World's Smallest Crankbait)

Bomber Model A Crankbait 2 1/8 Black Pearl 5/16 oz.

Small Creek Troutin

What The Little Fish Are Saying - Fly Fishing, Gink and Gasoline, How to Fly Fish, Trout Fishing, Fly Tying

3 flies you hate to love Hatch Magazine - Fly Fishing, etc.

The Value of Simplicity

Fly Fishing In Small Creeks: What Gear Do You Need

Artificial Bait Plastic Fishing Lure Bionic Sinking Fish Lure Fake Fish Crank Bait, Type 2

In Praise of Simple Flies

Artificial Bait Plastic Fishing Lure Bionic Sinking Fish Lure Fake Fish Crank Bait, Type 2

Trout Flies: When to Go Big, Small, or Tiny