Sealevel-
Yew, like most woods tends to show twist in the bark. If you look carefully, you can usually see the twisting in the tree. Sometimes yew grows tall and straight, sometimes it is more bush or shrub like. Some guys will cut yew for a billet or two, I simply can't do it unless I'm getting at least one, usually two staves. Here is a picture of some that came out really nice form the more bushy style yew trees.
Bryan
Here are some salvaged logs. You can see some twist in most of them. I was only able to get 1/4 staves and the rest billets or firewood.