According to the Environmental Protection Agency, Americans throw away about 1.6 billion disposable pens every year. The greenest upgrade is to invest in a refillable pen and use that in lieu of disposables. But a more realistic approach is to limit the number of disposable pens you take from hotel rooms, banks or as freebies from promotional events. Also, if markers or permanent pens no longer work, they may not be ready to throw out. Try dipping the tip in rubbing alcohol; this can "undry" the ink and make the markers as good as new again.

When it comes to shopping green, it's always a good thing to look for products made from recycled materials. But when it comes to buying toilet paper, you may want to think twice about buying recycled. Recycled-content toilet paper is made from paper items like copy paper, junk mail and magazines that are shredded, pulped, de-inked and re-processed. But paper receipts -- also known as thermal receipts -- can sometimes end up in the recycling stream. These receipts are coated in the chemical bisphenol A (BPA), a known endocrine disrupter, which can end up in recycled toilet paper. To avoid BPA, look for unbleached, virgin product instead.

When you go to the beach or pool this summer, sunscreen is a must-have item. But leaving a bottle exposed to the sun can make it useless; high heat can kill the active ingredients in sunscreen, making your lotion worthless. To keep your sunscreen active, try placing it somewhere cool, like a cooler with ice. Or fill a reusable cup with cold water and place the bottle inside. And when you get home from a day of fun in the sun, store the sunscreen in a cool, dark place.