I've tried a satin stitch but it just won't lay flat against the crocheted fabricWhat do you guys use for faces on your amigurumi dolls?
I agree with the first answer as far as the strategyWhat I would suggest would be to use a stranded worsted weight yarn (2 ply, 3 ply, 4 ply, etc.), then cut a length and separate the strands like you would embroidery floss for cross stitching and use just 1 strandThat way it takes a LOT of the bulk out of the stitch, allowing it to lay a little more flat.
You can use curb inlet filters for sediment control or Dandy bags