I first came across using a Linen Stitch on the sole stitches for socks here from Knitty. In this pattern it is necessary to work an extra row in the sole stitches for every four rows of instep when knitting in the round. This is because of the density and non-stretch in the Linen Stitch.
I wasn't following the pattern on my Graphite Socks exactly and realised that my Linen Stitch wasn't EVERY row as in the pattern. I was making alternate rows of all knit stitches. This worked well but the stitch was still very "tight". To overcome this problem I used a size larger needle when working my sole stitches. It still required me to make an extra row but only every 16 rows. You may prefer to add the extra row at lesser intervals than 16 rows. I refer you to the pattern mentioned above as to how this extra row is done.
So my linen stitch for sole stitches works like this on an uneven number of sole stitches only. The instep stitches are worked in pattern/stitches of your choice.
Row 1: K1 [K1, Sl1p wyif] until two sole stitches remain, K2.
Rows 2 and 4: K all sole stitches.
Row 3: [K1 Sl1 wyif] until one sole stitch remains, K 1
Abbreviations and their meaning can be found here