i usually don't pinch unless the tree refuse to give me figs. typically, pinching is not really needed unless you are looking for increase in production or branching of the tree. some trees are so busy growing leaves and branches, they refuse to put on the figs. if you wait for 3 yrs and don't see any figs on your tree, it might be the time to pinch. after about every 6 leaves or so, you literally pinch off the terminal bud on that branch. it will soon put new bud and branch out in different direction. if you don't like the direction it's going, pinch that off too. soon it will put on the figs and new bud that will become new branch and since main crop figs are on the new growth, more figs.
some members will let the tree grow as it will for about 2-3 yrs then start pinching and punning to the way they want the tree to look.