Next thing to worry about once you you have is putting your hook into the vice. The operation of each different type of vice is different so you'll have to get familiar with how your one operates.
There is too camps when it comes to hook positioning those who put the point of the hook in the jaws and those who don't. I'm firmly in the point out camp, all the fly tiers I know put their hooks in the vice this way.

The point in placed inside the jaws of the vice, this method gives a less secure hold as less of the jaws are in contact with the hook. I have taken a chip out the jaws on my own vice trying this as the hook slipped while tying a fly taking with it a small piece of the vice as well.
This method also restricts a large portion of the hook from being tied on easily, as the picture below shows, all of the hook on the left of the line is difficult to tie onto due to the jaws being in way leading to strange wrapping techniques to overcome this.
The picture below shows the best way to position the hook in a vice in my opinion. The hook should be placed with the lower half on the bend of the hook in the jaws of the vice. Make sure you place the hook at a sensible distance in from the tip of the jaws especially with a regent style vice which can shoot a hook across a room.
That's all,
AL
PS. does anyone think there's something more that could be added to this?