Knitting a cap - design discussion (updated)

Having knit a few caps, here're some notes on the design:

Number of stitches to cast on = 0.85 * stitch gauge (in stitches per inch)* circumference of head (in inches)

If you like a warm ear band of height h:

cast on provisional, knit h inches, purl one row, knit another h inches. Now fold over (along the purl ridge) and join the cast on stitches to each corresponding live stitch. Alternately, you can hem it together during the finishing.

To make the inner flap snug, use 2x2 rib instead of plain stockinette.

Other techniques for making the ear band warmer:
1. Fair Isle/colour stranding: this creates a double layer, making the ear flap 3 layers thick.
2. Line with soft felt. This although may seem like work, will make the cap that much more wearable in winter.
3. Knit ear flaps like the South American Chullo. To make this, first knit 2 ear flaps for desired length which you can join at the appropriate positions once the ear band is knit for 2 rows.

Update:
The no-rib ski cap I'd knit recently hadn't turn out quite as warm around the ears as I'd wanted, possibly because of the acrylic content in the yarn. Also maybe due to a lack of colour-work or ribbing. So you see, the 3 points I'd written above were what I learned from the project. Option #2 seemed to be the best fix and I got right down to the task. I knit and fulled 2 strips, placed them on the inner side and hand-stitched them in place.

The no-rib ski cap with colour stranding

Inner flap lined with fulled strip

Here's to a toasty cap!