1. each scarf should be reversible, that is, it should have no wrong side and preferably be one whose two sides are identical or very nearly so;
2. the pattern stitch must be easy to remember so I don't have to carry its instructions with me;
3. the fabric must have some texture, in the form of pleats, welts, or pockets, to help trap heat so I can use lighter weight yarns; and
4. the scarf should be a bit out of the ordinary in looks.

I found a number of patterns which meet these criteria. Here are four of my favorite reversible pattern stitches from this group. Using sport or DK weight yarn and the size needle you would normally use for this yarn, cast on 40-50 stitches (or around 30-36 for the Syncopated Brioche Stitch) for a 5-7" wide scarf (unstretched) and knit until you reach your favorite scarf length. Do not block; steam lightly only if necessary to retain as much heat-trapping texture as possible. Fringe is optional.

• MISTAKE STITCH RIBBING -- Multiple of 4 sts + 3
  

  Every row: * K2, p2; rep from * to last 3 sts, k2, p1.
  
  
  

• SYNCOPATED BRIOCHE STITCH -- Even number of sts
  

  Row 1 (preparation row) : * Yo, sl 1 wyib, k1; rep from *. 
  Rows 2-7: * Yo, sl 1 wyib, k2tog; rep from *.
  Rows 8-13: * Sl 1 wyif, yo, p2tog; rep from *.
  Repeat Rows 2-13 to desired length.
  Final row: *K1, p2tog; rep from *. 
  
  
  

• MOCK KILTING STITCH -- Multiple of 7 sts
  

  Rows 1 & 6: * P6, k1; rep from *.
  Rows 2 & 5: * P2, k5; rep from *.
  Rows 3 & 4: * P4, k3; rep from *.
  Repeat Rows 1-6.
  
  
  

• GRAND PICOT EYELET -- Multiple of 3 sts + 4 edge sts
  

  Row 1: K2, * sl 1-k2tog-psso, [yo] twice; rep from * to last 2 sts, k2.
  Row 2: K2, * [p1, k1] into the double yo, p1; rep from * to 2 sts, k2.
  Row 3: Knit.
  Repeat Rows 1-3.
  
  
  

Part 2 of this series will focus multi-colored reversible scarves.