Did you miss this post over at Liberate Creativity? 
In case you did, (and because I am waiting on a piece for my sewing machine, and my laptop is getting repaired talk about luck) I thought I would repost it here. It is my favorite cardi, and I am not afraid to admit with the spring like weather my daughter has been wearing it everyday that it is clean it may be time to make a few more… 
it’s just the perfect little cardigan for any age, that adds a little sophistication to any outfit.
Want to make on too? Great let’s get started! First with the pattern:
Grab a shirt that fits well, a little loose is best. Turn it inside out.
1. Smooth it out flat
2. Then fold it in half 

3. Line the folded edge up along the edge of the paper. (any paper that comes in a long roll works well)then trace the out line of the bodice.
4. When you get to the arm opening fold the sleeve in and make sure the entire seam is showing and laying flat. Then trace.

Then you have a bodice piece (for the sweater we will use the same pattern piece for the front and back)

Next for the sleeve:
6. Line the sleeve up with the fold of the sleeve against the edge of the paper and trace the arm.
7. When you get to the top, fold the shirt over so the seam is exposed and laying flat and trace the curve.

Next you will want a neckline piece. To make the pattern for that:
8. line the bodice piece pattern up to the edge of the paper and trace the neckline.
9. Then move the bodice piece and following the curve of the neckline draw a line that is about 1.5 inches below the neckline.
*This will be the neckline piece for the back neckline you will do this same method to make on for the front after the front neckline has been cut.*

Then to cut out the pieces I used this white sweater that was in the “re-do” pile at my house. Any sweater will do, just find a sweater you wish was a cardigan.

Cut the back bodice piece on the fold. I line it up with the bottom of the sweater so that I don’t have to finish the bottom edge.
9a. Then with your front piece you will cut two bodice pieces not on the fold but add 2 inches on the front. (picture 9a. shows the back piece on top of the front piece)
9b. Now cut the neckline a little lower for the front pieces and then make the neckline pattern piece.

For the rest of the pieces I cut the sleeves on the fold out of the arms of the sweater so they lined up with the bottom of the sleeve.
Then out of a silk fabric I cut one neckline piece on the fold for the back and two not on the fold for the front.

Now for the sewing.
(my camera had some corrupt files so a few steps went missing, but I will walk you through it and the picture should help)
10. Sew the back neckline piece to the front neckline pieces at the “shoulders” Then sew the front bodice pieces to the back bodice piece at the shoulder. The with right sides together sew the neckline piece to the neckline of the sweater. Turn it around to the inside and topstitch in place. (picture 10 shows up to that point)
11. Pin the sleeves in place at the arm opening. I put a few small pleats in my sleeves so they would have a little fullness. Then sew it in place.

After the sleeves are sewn in place.
12. Fold the sweater so right sides are together and the front and back match up. Then as the dotted line shows, sew starting at the end of the sleeve to the armpit then turn and go down the side.
13. Next tuck under the remaining raw edge of the neckline piece and topstitch it in place. Then fold under the front edge and topstitch as well. This should leave you with all finished edges.

Next measure the inside of the cardigan starting at the front left across the back tot he front right. Then cut out a strip of fabric ( I used the silk again) that is the width of the sweater and the height of your elastic plus 1 inch so you can turn under the edges. Turn under the top and bottom edge, and then pin the strip through the middle of the cardigan. Sew along the top and bottom but leave both ends open. This creates an elastic casing.
*You want to be careful to smooth out the sweater and try not to stretch it as you sew.
14. Next slide elastic in through the opening and sew it in place on both sides. The elastic should be the width of the waist that will be wearing the cardigan when stretched a little.
15. I tucked the corners down and sewed them in place so that the cardigan wouldn’t flap outward. You could have cut this off at the beginning as well but I find that folding it inward and sewing it in place adds a little stability. Your choice. 
Next I measured the sweater from the shoulder down the front and made a strip that was twice as wide as I wanted the front ruffle (since it will be folded) and twice as long (since it will be gathered)
16. After I cut the strip I folded it in half and ran a basting stitch down the raw edge. I gathered it to the length I wanted and then zig-zag stitched (or you can serge) the raw edge. Then since I used silk which tends to fray I took my lighter and very carefully melted the raw edge so it wouldn’t fray.
17. Then I pined the ruffled piece along the front edge. One on each side and sewed it in place.

Lastly I added a button
18. I sewed a button on the right side and I folded a small piece of elastic in half to create a loop and sewed it to the inside of the left side. The loop goes around the button.