Make a Budget: You can't save money if you don't know how much you spend.
Mint.com's free app for Android and iOS helps you get a handle on how much money is coming in, and how much goes out. With the app, you can enter purchases as you make them to keep an accurate account of spending. The app also creates budgets for categories such as eating out and entertainment. The app works as an excellent extension to Mint.com's online finance-tracking service.
2. Sell Your Old Stuff: Amazon Marketplace is great for selling things like books, clothes, and accessories. It only takes a few minutes to set up shop, and you don't have to deal with the hassle of auctions like on eBay. Set your price, and Amazon will let you know if you need to tweak it to be competitive.
3. Keep Tabs on Tips: You'd be surprised how often restaurants and other businesses mistakenly overcharge customers because they misread the tip amount that's written on a bill. Log onto accounts once a day to double-check that everything is accurate. It takes a minute, and catching those mistakes means cash in your pocket that you'd otherwise be kissing good-bye.
4. Shop on Mondays: Department stores typically mark down items on Sunday night or Monday morning, so you'll get first dibs.
5. Use a Credit Card That Gives Cash Back: When you buy things this way, it's like you're getting free money with every purchase you make. Check out BankRate.com to figure out which cash-rewards credit card is the best for you. The site makes it clear what the interest rate is, if there's an annual fee, and even how clean your credit needs to be to qualify.
6. Tweak Your Phone, cable, or satellite Plan: If you've had the same contract for more than a year or two, there's a good chance you're paying too much, since newer plans are rolled out all the time. Still, it's annoying to call around to find the best deal, so let BillShrink.com do it for you. The site will ask you a few questions about your usage, and then show you the cheapest plans that fit your needs.