My first color I used I crocheted until I ran out but fell short of finishing a round. I didn't like how that looked so I from then on I try to use up as much as I can and only go as far as my scrap ball of yarn will complete a whole row.
I am really liking how it is turning out, but it is getting harder and harder to use just my scrap balls of yarn. They seem to small, and the larger the blanket gets the more yarn it needs to make a complete round. I will keep going until I am happy with the size and if I do have to use new skeins I will.