Hi Samten,
I did see your other post and to be honest I am not at all sure how you are making your baby's poncho which is why I did not answer sooner. If you're going to make it like a cape starting at the bottom and working up to the top, you need only continue decreasing to the neckline and then increase again at the back of the head till the hood is big enough to fit around the head, then decrease a couple of rows to shape it.
If you're using the method of making rectangles which are then sewn together, then you can pick the stitches up round the neck area and decrease till you have the right number of stitches for the neck, then increase at the centre back until you have enough stitches for the hood. Either way you'll cast off at the top, fold the seam in half and sew it up.
Have you got a pattern for this or are you working from scratch?
