Am knitting a jumper for DS in a rather fetching jockey design, but it has a large intarsia star on the front. I've knitted patterns before but have always carreid the wool across the back. This is too big, plus I'm a bit low on the main colour wool so don't want to waste any. The pattern instructions say 'twist the wool together' - how? Do I carry it across the back ofr a couple of stitches? How do I avoid big holes?