If you have plants inside of your residence, consider reusing plastic bags to create hanging planters. Gather two or three bags (you need more than one for additional strength and reliability). Fill the bags up with some soil and your favorite plant. Voila -- you have a cheap and highly effective hanging planter.
If you occasionally have to go on long car rides, plastic bags can go a long way (especially if you are bringing along some messy kids). Throw a few plastic bags into your glove compartment for trash purposes. From fast food meals to snack wrappers, plastic bags can make keeping your car neat and tidy a much easier task.
One unusual and creative application for plastic bags is to make knee pads for gardening or working around the house. Simply tie a single bag around each of your knees. This can work well to cover the parts that would otherwise be exposed to dirt.
Plastic bags also can be helpful for packing for trips. If you're packing a suitcase and want to bring along an extra pair of shoes or two, the last thing you want is the bottom of your shoes making contact with your expensive evening dress. To avoid this, save plastic bags and use them to tightly wrap up any footwear. That way you can pack your shoes and clothing next to each other without the possibility of soiling.
One of the most irksome aspects of the winter months is having to scrape off your car. If the forecast calls for snow or ice, cover both the windshield wipers and the mirrors of your vehicle with plastic bags before the bad weather hits to save yourself the trouble and time of scraping ice off in the morning when you're already in a rush to go to work.
If you are an artsy type who enjoys participating in arts and crafts, plastic bags work wonders for protecting surfaces from staining and other damage. If you do not want sticky paint to get all over your wooden table surface, cover it up extensively with as many plastic bags as necessary.
Defrosting can be a soggy and messy process. If you're leaving meat out on the counter to defrost, you probably want to avoid the cleanup afterward. Contain any juices that might pour out with a couple of old plastic bags.
If you're sending something in the mail that is on the fragile and delicate side, fill your package or envelope with a bunch of old plastic bags instead of wasting money on pricey mail fillers such as bubble wrap.
If you have school-aged children, pack their lunches in plastic bags instead of purchasing the classic brown paper bags. Also considering doing this for your lunch at work. Plastic bags are much less likely than brown paper bags to tear (you can avoid your child spilling potato chips all over the insides of her backpack).
On wet and rainy days, umbrellas can be really messy and annoying, especially when they drip all over the floor and furniture. Upon coming back inside from the rain (whether you are at your own home or another person's), simply fold up your umbrella and place it in a bag.