I love this question. We are all guilty of wasting money at some level, but is it guilt or is life to be enjoyed? I think the answer is somewhere in between. When I was saving to pay for graduate school and then a house- we had a tight budget, regular paychecks and not a lot of wiggle room. And while I wasn't organized enough yet for a budget, a simple plan was enough to squirrel away about $10 grand over the course of a year. First, I took out a set amount of money from the ATM every Monday. this was my "walking around money" for coffee, lunches, drinks. Set that to about $40. Not much, but what do I really need in a 5 day work week? Second, we only ate dinner out once a week OR got take out. ONCE. Sometimes we'd get lunch on Saturday. There are some more obvious ideas too- don't overspend on a car- get no more than you need, buy used but reliable.
More tips:
Don't overspend on a rental apartment- get the cheapest place that suits your needs while your are saving to buy a house.
Don't stress about buying status items, you don't need $150 shoes, and if you do, you only get one pair.
Don't go on vacation and stay in a $450/night hotel when the budget place or a hostel will do just fine, but do enjoy a vacation, life is to be enjoyed.
DO: get a second job a couple days a week, doing whatever, near your home- make $200/wk- it fills time (which prevents spending), can be fun, and adds up to a lot after a year.
And remember: If you save $27.40/day it adds up to $10,000/yr. That is a pretty easy thing to do.