Choosing a good durian is summed up in three steps - See, Smell, Feel. See the stem for its "green-ness", that's an indicator of quality. Then, smell. Put your nose to the sides of the durian and breathe in. It should smell pleasant, not overly strong, or it could be overripe. Last, feel. Knock the fruit, you should feel its seeds moving slightly. When all three boxes are ticked, buy it!