This time of year is when I always prune my grapes. I then know which branches are dead and which are going to be trained. All of my varieties are grown as single stem cordons. Some years the stem may be cutoff to allow a better new stem to take over. The below photo is a typical variety with one years growth.
The general aim is to have just one main stem and only new side shoots. These shoots will have the bunches of grapes. During the year these shoots will be cut back to one leaf beyond the fruit truss. Dependent on the variety, these bunches of grapes may well be cutoff to have only 2 bunches of grapes per cordon.
You will notice that I have used sisal twine in the past as ties. This lasts for 2 or 3 years and it rots down and falls off. Due to the quantity of ties and to speed the process up, I know use a commercial machine.