This is my personal favorite! Think of yourself as a regular monthly bill you have to pay. All you have to do is arrange to have a set amount of money directly deposited from your paycheck into a savings account each month.
I recommend using a separate savings account because if you have access to your funds in your checking account, you're more likely to spend them. Again, it might hurt a bit at first to take home a little less every month, but trust me, after a while you won't even notice it's gone. Here's a moment when the "set it and forget it" strategy works wonders.