First, I consulted Ravelry, and was rewarded with helpful advice, offered in this thread on the Sock Knitters Anonymous discussion board. I planned at the outset to purl the soles of the socks, putting the smoother stockinette side against his sensitive soles. Commonly known as a "Princess Sole", this technique is a bit more troublesome, but makes a more comfortable sock.
I knit this sock from the top down, and planned to use a slip-stitch pattern to make it similar to the socks my friend had tried and liked. However, the Wildfoote yarn I chose is too splitty to work well with any stitch more complicated than plain knits and purls. The pattern I originally selected began with a k3, p1 cuff. When I decided against doing the slipstitch, I simply continued the cuff pattern on down the leg. About halfway through the leg, I realized that although the k3, p1 ribbing was smooth on the outside but produced a "bumpy" inside. I was afraid that the single k1 rib would rub against my friend's leg and irritate his sensitive skin.
After all, a person with tiny little feet and such sensitive soles must have tender skin on his leg, too.
When I began the heel flap, I turned the sock inside out, placing the smoother k3 side of the knitting to the inside. Now I can't decide if I should call these Socks for the Tenderfoot or Inside-out Socks.
About a half-inch before the heel, I added an additional purl stitch to the pattern, making a k1, p1 section across the instep to allow more stretch there. Once I knit the heel, I continued this k1, p1 for another half-inch before switching to plain stockinette for the foot.
You can get a better view of the pattern I used for the heel and the Princess Sole here. It continues the slip stitches for the heel under the arch of the foot, then purls the sole. I'm sorry I can't model this sock for you. It is a bit too short to fit properly. I was so eager to see if the Wildfoote yarn softened up after washing that I knit the toe too soon. The Wildfoote does soften a bit, but it doesn't grow much after washing and blocking. Once I get a better fitting second sock knit, I will rip out the toe of this one and reknit it to match. You'll see modeled photos then.
Of course, such a plain knit sock is not that interesting or inventive. I've provided these details here in case you have a tenderfoot that needs socks. I also have a simple method to knit them with minimum purling. Click the link below for the free pattern.