One good MM is that avoiding excessive trading can mean taking too many trades at a time, thereby increasing your risk exposure to the market. This could also mean trying to chase a pip across the market by placing too much trade in a day, especially after a defeat in an attempt to get back a portion of what was lost. Whatever it is, you risk losing a lot and this is a great and simple way to talk about money management. But I would say that you also need a good strategy. You can't just use any strategy with a good MM and make it work. You need both parts - strategy and money management - three actually - you also need psychology to hold trade.