These are two muffs I made for a dear friend's granddaughters. They were lots of fun to make!!!
Easy peasy.
I'll give the pattern for the pink one and you can make modifications?
Supplies: Fun Fur Worsted Weight Yarn 4 size 6 DPN needles (or what ever you feel comfortable knitting with, the six's were tight, but doable)
using knit CO , cast on 36 stitches 2 yarns together (or any amount divisble by 6).
Knit until "muff length" or you get tired of the fun fur.
Break Fun Fur, leave worsted weight yarn
Row 1: p Row 2: *k3,p3* Row 3:*k1,p1*
Repeat Rows 2 & 3 until when lining is folded over it is about 1 inch less than the muff length. This part is tricky. You want to now insert the lining into the muff, and you might have to actually take off the needles to do this, but take it slow and be patient. BUT, I just realized that if you turned the muff inside out BEFORE you started the lining, it would be MUCH easier to do....just play with it. The end result is the lining inside the muff, and live stitches are next to the CO stitches.
Now, one by one, pick up one of the CO stitches, and K the first stitch on the needle together with the CO stitch. I use the K2tog bind off method for nearly all my bind offs as it is VERY stretchy and loose.
In a rhythm it goes like this:
1. Pick up 1 cast on stitch and put on left needle
2. Knit CO stitch together with first stitch on left needle
3. Repeat 1 & 2
4. 2 stitches on right needle
5. K 2 sts on right needle tog by placing left needle in front of both stitches and knit.
6. Repeat 1-5 until all the way around. 7. Break yarn, pull through loop, and tuck the tails into the muff and you are done.
Not terribly sure how "kosher" this is, but it worked for me and it was SECURE. 
