I have just had crochet on the brain for the past week, literally. Dreams and all. So I have been doing a lot of "swatching" regarding this scarf and came up with some of good parameters: Single Crochet (SC) makes a more spirally effect than Double Crochet (DC), even if you start off the first set of rows with SC and then switch the next set of rows to DC. If you end on an increase row it will give a lacier effect to your scarf. This is especially true with DC if you are using a fine mohair. If your mohair is weightier you still get a nice lacy effect, but it's a little heavier. The edge will get more ruffly (not spirally) if you 5 Shell into every other stitch (SC, 5 Shell repeat) for the final row. This is not really the case with a 3 Shell, though. It's a lot more work for a little effect. The 5 Shell will make the edge of the scarf heavier looking and you will lose some of the lacy effect mentioned above. (see picture) If you want double the ruffle, then pick up m...