Place the chopped chocolate and salt into a metal bowl.
Bring the cream and butter to a boil, and pour over the chocolate. Whisk until well combined.
Whisk in the alcohol, if using, or just add a teaspoon or so of vanilla.
Pour your ganache into a shallow dish, cover, and refrigerate until firm (several hours to overnight).
When ready to make your truffles, make sure you have a fairly large work space.
Wearing thin latex gloves will keep your hands clean and keep the ganache from melting too quickly in your hands.
Have your rolling options in shallow pans-aluminum pie pans work well.
Using a melon baller or just a spoon, scoop up some ganache and roll it quickly into an irregular ball shape. Drop the truffle into one of the pie plates. Once you have rolled ten or so truffles, shake the pie pan(s) to completely coat the ganache. Place finished truffles on a plate or in a storage container. It is easiest to have a separate container for each type of truffle you are making.
Refrigerate the truffles for up to two weeks, or freeze them for up to two months. You can serve them right from the refrigerator, but they are best if you let them sit out for a half hour or so before serving.