My very good friend Jonathan never wanted me to make him anything which was hard for me as I love to knit/crochet things for people. FINALLY one day we went to my LYS and he picked out this yarn and said I could knit him a headband. So I did. Then he loved it so much he wanted matching armwarmers. So I made these armies up. Very easy and no seams (which I love).
It's summer here in NZ, but next winter he will be pretty stylie. They are very easy and very quick. And you make them to fit quite snug since I find crochet stretches.
Please let me know if you have any problems. I always just make stuff up as I go along, and this seems pretty straightforward to me, but it may not be!

Hummingbird Aires Fast Knitting 50g
4 skeins

custom fit - you decide the size

12 sc = 4" (10cm) I think

(Make 2)
-Ch34
-Sc into 3rd chain from hook
(Make 2)
-Sc across all chains (32 sc)
-Ch 2, turn. Sc into all sc.
-Repeat these rows until the rectangle is large enough to wrap around you arm with a snug fit.
-Last row, fold your rectangle so that the beginning row is in line with the last row. Work sc through both the first and the last row for 5 sc. Work 6-8 sc only on one row (up to you, this is for the thumb hole). On 7th or 9th, begin sc through both rows again. Sc through both rows until the end. Pull ball of yarn through loop to fasten off, but don’t cut yarn.
-At the cuff, pick a loop, pull yarn up and through (you are now working in the round at the cuff), chain 2. SC through loops around the edge until you reach the beginning of the round. Sl st. Ch2, turn. Sc back the other way to the beginning of the round. Sl st. Continue in this matter for 4 more rows (or however much longer you wnt to make it – if you go too far up the arm you will have to increase about 4 more sc evenly over the round to make room for the upper forearm). Fasten off. Weave in ends. Long armies with no seams!!