Row 1: in 4th ch from hook, (dc, ch2, 2dc), *sk 4 ch, (2dc, ch2, 2dc) in next ch; rep from * across to end
Row 2: ch6, turn, (dc, ch2, dc) in 4th ch, (2dc, ch2, 2dc) in every ch2 sp across
Row 3: ch1, turn, sl st to 2nd ch2 sp, ch3, (dc, ch2, 2dc) in ch2 sp, (2dc, ch2, 2dc) in every ch2 sp across
Repeat rows 2 and 3 until your scarf is the desired width or almost out of yarn. Fasten off, and weave in all the ends.
This scarf is 13"x75". The increasing at one ends and decreasing at the other forms an interesting parallelogram shape. The scarf hangs nicely with this, as it kind of drapes down.