Not really a specific way but there are better methods then the rest. It depends what type of bowl you have. If you have a smaller bowl you can usually just light all of it and snap it. If you have a larger bowl, make sure you corner it and keep inhaling just enough to keep the ember going. take your time and make sure that you aren't inhaling too fast or too slow. I have a 19in bong that i milk whenever i smoke and a pretty large bowl that i usually smoke with friends. Whenever im smoking alone i pack it completely then just corner it, keep the ember going until the chamber is full, take a quick breath then rip it. hold for 4-7 secs...then release. IMO the most important part of milking a bong is making sure that your not wasting bud. To do this you corner it and keep the ember barely alive so it burns slower resulting in more smoke from less bud.