Because several persons asked, I have worked out a recipe for my Crochet Vest from a Blanket. This is not a pattern because I just measured what I did and didn't check gauge or anything. So you simply work to the inches stated at whatever gauge you have.
Chain about 40", which goes over the shoulder as long as you want. You might want to add a couple stitches for the over-the-shoulder part. If you want the vest to be longer, crochet more.
Work even for 6". On the next row, work 18" and STOP. Work even on these stitches for 5.5", making sure to end at the neck. Cut the yarn and reattach it 6" later, then work even on the remaining stitches for the same number of rows, so that you end up on the edge. The front will be about 16" wide, so you have a 16" piece, a 6" blank, and an 18" piece. If you made the beginning chain longer than 40", add evenly to the 16" and 18" pieces.
NEXT ROW, to join on the other side of the neck: Work even on all stitches, chain the same number of stitches you skipped for the neck, and work even on the back. Now work even on these stitches for 6".
End off. Fold in half (the neck hole should be unevenly set, so you have a higher back and lower front) and sew the sides for about 12". Work a couple rows sc around the arms and neck, and around the bottom if you like. Done!
Please let me know if you have any questions or problems.