Inspired by this famous fellowship image.

The chart pattern is 26sts, but in total the total pattern i made my scarf in was 30 sts, but you can ad more if you want more sky or ground. The first and last stitch knitted together both colours, to get a nice edge, but that is optional, and everything was in standard double knitting.

Any yarn is fine, I used yarn about as thick as my needle, so about 2.5mm. My swatch suggestion would just be to knit a hobbit, and see how it turns out, if they feel to skinny, add one extra fattening line in the middle.

The tree of Gondor pattern was found here (though I shrunk it a bit to fit):