The ProcessStart with at least 350g of chocolate. A large amount like this is easier to work with, especially for beginning chocolatiers.
Chop chocolate into even pieces that are no larger than about a centimetre square. Use a knife to scrape the chocolate to the dry bowl. If you use your hands, move quickly: the chocolate will melt in your hands.
If you're using a double boiler, make sure the water in the pot is not touching the bottom of the bowl. Bring the water up to a simmer, then turn off the heat before adding the chocolate, or keep it on low heat. Always wipe the condensation off the bottom of the bowl when removing it from the heat; water can cause melted chocolate to "seize."
In the microwave, place the chocolate in a glass bowl and zap it on high power for 30 seconds at a time, stirring after each interval.
Using a sugar (or cooking) thermometer
A sugar thermometer helps when tempering chocolate. But if you don't have one, you can use your lips to gauge the temperature, since they are significantly more sensitive than your hands. Keep in mind that 50 degrees is a bit warmer than your lips (not hot!), 26 degrees will feel cool (although the chocolate will be mostly liquid), and that 32 degrees C is just slightly cooler than your lips.