I have used this pattern many times for different scarves. You can vary the number of stitches you cast on to vary the width of the scarf. I have also not included a specific number of rows since different people prefer different length scarves. Also, take into consideration the height of the person you are making the scarf for when determining the length.
Cast On 45 stitches via long-tail cast-on method.
Row 1 – K3, P3 all the way across.
Row 2-End – Repeat Row 1 until scarf has reached desired length.
Bind off and weave in ends.
*Note: I claim no copyright to this pattern as it is, obviously, a very simple and straight-forward basic knit pattern.