Sure, shopping at flea markets, tag sales and garage sales is a great way to save money and reuse items, but as green as it is to shop at these sales, there are certain items you should never buy. One item to avoid is used cookware; since Teflon and the chemical PFOA are being phased out in cookware, older pots and pans can still have it. But older cast-iron cookware is fine to buy, even if it's in worn shape. It's easy to refurbish old cast iron.

Have a hard time remembering to water your houseplants? Here's a way to keep your plants alive and recycle old sponges all in one. When it's time to replace an old sponge, disinfect it by placing it in the microwave for about 90 seconds. Put the cooled sponge at the bottom of a planter. This will prevent soil from falling out, and it will also absorb excess water each time you water the plant. The wet sponge in the planter will slowly release needed moisture, helping to keep the plant alive in case you forget to water.

If you want to make one home improvement upgrade that doesn't cost a lot and can help you save money, install a whole-house fan. Unlike a tabletop or ceiling fan, this one is fixed into your attic and helps force hot air through your attic vents while drawing cooler air into your home. This upgrade can have a dramatic effect on the cooling of your home during the hot months and reduce your dependency on central air conditioning altogether.