If you are in twenties or early thirties and remain single, earn $3,000 after tax per month, you will probably save $1,000 if you, let's say, spend $500 to $800 on rental, a guest bedroom in a shared house/apartment, $500 on food, $50 on utilities, $150 on phone/internet bills, $400 on commuting costs or gas/maintainance if you have a used car, $200 on occasional entertainment or others. This $1,000 savings will allow you to invest or place a house down payment when time is ripe. Is this possible based on where you live ?
It can actually be quite hard because it's very easy to spend your free cash on living a fun life and it shouldn't be looked down upon. You really have to find the right balance, because while it is good to save and invest - you can quickly lose all the best years of your life living like a hermit. It's better to spend some money on travel or other toys that might help to broaden your mind. For some people a quarter might be all they can put aside each month, if you have a much larger income you might only spend 10% and can save the remaining 90%. The age you are at can make a huge deciding factor as well, because when you are younger you have more time to recover from mistakes than accidentally losing everything just before retirement.