Someone lives comfortably on 90% of what you're spending. Copy that person and put 10% away. When you get a raise, save it. You're living comfortably on what you have now -- you can afford to save it.
You cannot afford to buy as much house or as much car as the salespeople say you can afford. If you have to stretch to qualify for something, you can't really afford it.
Every now and then, write down every penny you spend for a week or two. It'll help you notice "leaks" in your financial plan. Very often once you KNOW your weaknesses, you can find a way to spend less. For example, if you're putting $2 a day into the snack/drink machines at work, start buying snacks at the grocery store and keeping them in your desk.
Saving change in a pickle jar isn't really saving. It's just keeping your cash in a different location. To SAVE, you have to spend less and bank the difference.
Do not be fooled by cashiers who tell you, "You saved X amount today." You save money in the bank. You don't save while buying new shoes -- that's spending.
I have a rule about buying clothes: When I buy something, I almost always leave it in the bag in the closet for two weeks. If I take it out and still love it, the tags come off and it's mine. But more often than I'd like to admit, I take it out and realize that I really don't love it. Or, like I did recently, I realized that I already have two orange dresses -- you'd think I'd have remembered that. So it goes back to the store.
The grocery store is convenient, but it is the most expensive place to buy food. Search out other options. I buy vegetables at a Farmer's Market in the summer, meat from a local farm co-op, spices from a health food store, various things from ethnic grocery stores, a salvage store and more. I don't shop at these places every single week; for example, my favorite place to buy spices is a good hour away, so I wait 'til I'm going that direction anyway, and I make a list so I get everything at once -- I probably go only twice a year.
If you're trying to lower your grocery bill, start with beverages. The average person spends 30% of his grocery bill for beverages, most of which are unnecessary for good nutrition.
Learn to cook dried beans: Cover with water in a crock pot, let them soak overnight, then leave them on low all day long. A $1 bag will provide two meals for your family. Pinto beans, homemade cornbread, and a glass of milk is fine eating!
Shopping should not be a hobby. Walking around the mall usually results in spending money -- you almost always see something that you "need", although the "need" didn't exist until you saw the item. Or you'll see a "bargain" that you don't really need but can't pass up.
Credit cards are tools. They can be used well, or they can use you. If you're tempted to buy something that you can't pay off this month, ask yourself what you'd do if the card weren't available. Usually the answer is rather painless. Rarely is it really necessary.
Any time you're going out to buy a certain item, check the internet for coupons. Quite often, I find a coupon for Rack Room Shoes, various restaurants, AC Moore, and other places. It takes very little effort to check. Sign up for coupons to come to your email.
Buy used. Not only is it good for your wallet, it's environmentally sound, and if you're buying from an individual you won't pay taxes.
Search for the least amount you can use. What if you use half the shampoo you're currently using? Half the laundry detergent? Try it. If it's too little, go back to using more, but often you'll find that less is acceptable.
When you're making a casserole or a sauce, always make double. Freeze half, and you'll have a ready-to-serve meal one night when you otherwise might've gone out to dinner.
Chicken thighs are a great bargain. I often see a HUGE package for $4. Boil them, and you can get 2.5 meals from them (chicken-and-dumplings, chicken soup, chicken-and-rice-casserole, chicken enchilladas, etc.) and also a couple free containers of chicken stock.
Learn to preserve food -- canning, dehydrating, etc. Buy plenty when food's cheap and preserve it for later.
Consider raising your insurance deductibles. Chances are pretty good that you won't use your insurance this year anyway, so raise the "you might pay it" money. In exchange, your premiums'll be slashed by about 1/3. And premiums are "you're definitely paying it" money.
Being in debt is very expensive, and getting out of debt is very difficult. It's easier to make small sacrafices to AVOID getting into debt than it is to make big sacrafices to get OUT of debt.
Within reason, raising kids can be as cheap or as expensive as you want it to be. And the results won't be all that different in the long run.
Pick the things that really matter to you, and spend accordingly. But none of us in the middle class can have EVERYTHING that we want, so skimp on things that aren't as important to you.
Keep a price book. It'll help you realize 1) patterns for sales; this'll allow you to plan ahead and buy enough of an item to get you through the next anticipated sale. 2) that all sales aren't really sales.