I have to be honest: it feels strange to me to write out a pattern for what I feel is an off-the-cuff, no-pattern-required scarf. Still, in my early days as a knitter, I would have really liked the pattern, even for "unvented" things like this scarf.
So I present to you:
by Anjela Bugher of http://sheeponmystuff.com
Approximately 200 yards of your choice of yarn, worsted weight. (Or about 1 skein of something you like. I used 1 skein of Dark Horse Fantasy, which is the nicest acrylic I have ever worked with.) This will make a short scarf, but it'll definitely make a scarf. Two skeins and you can make as long a scarf as you wish.
Set of needles to the gauge of your choice; roughly what it says on your ball band. Somewhere between 4mm and 5mm (US 6-8) will probably do well. (I used 4mm (size US 6) needles.)
Cast on a multiple of 6 stitches plus 3 — no fewer than 15! (I used 33: 6 x 5 = 30 + 3 = 33.)
You will be knitting on an I-cord border as you go, which makes the edges of the scarf neat and tidy. It will also make them just a little shorter than the rest of the scarf. It won't make your scarf roll up or prevent it from laying (mostly) flat, but it is something to be aware of!
Row 1: K3, (P3, K3) to last 6 st, P3, slip 3 as if to purl.
Row 2: K3, (K3, P3) to last 6 st, K3, slip 3 as if to purl.
Row 3: K3, (P3, K3) to last 6 st, P3, slip 3 as if to purl.
Row 4: K3, (K3, P3) to last 6 st, K3, slip 3 as if to purl.
Row 5: K3, (K3, P3) to last 6 st, K3, slip 3 as if to purl.
Row 6: K3, (P3, K3) to last 6 st, P3, slip 3 as if to purl.
Row 7: K3, (K3, P3) to last 6 st, K3, slip 3 as if to purl.
Row 8: K3, (P3, K3) to last 6 st, P3, slip 3 as if to purl.
(The idea here is that you're knitting the first three stitches of every row and slipping the last three stitches of every row — this creates the I-cord border. Meanwhile, with the center panel, you're doing a basketweave pattern which is 3 stitches of knit, 3 stitches of purl, for 4 rows — then 3 stitches of purl, 3 stitches of knit for 4 rows.)
Repeat these 8 rows until you run out of yarn or until your scarf is as long as you want it to be.
Cast off by knitting in pattern as established, but purl the last three stitches.