For a fun, easy project, you can't beat Plymouth Multiplicity! It's a lofty, bulky wool/acrylic blend that works up quickly on size 15 needles.
Just one ball, at 131 yards, makes a soft self-striped scarf.
I follow the texture in the self striping yarn, which is part solid color and part bulkier multi-colored, and let the yarn determine when to change stitches. Here's my recipe:
Yarn: 1 ball Plymouth Multiplicity
Needles: US size 15
Finished size: length, 60 inches/width, 5 inches
Loosely cast on 15 stitches.
When the yarn is solid colored- knit every row
When the yarn is multi-colored- *knit 1, purl 1* across, ending with a knit 1
Cast off loosely in stitch you're using at the time (either all knit, or knit 1, purl 1).
There you have it- no counting, no fuss!