Recycle your old glass jars by making them into something else. You can cut small jars to create handle-free tea and coffee cups. Trim down tall, narrow jars for vases and cut large, wide jars into shallow glass planters and casserole dishes. You can also use the resulting rings to make rustic wind chimes or sink them into the ground to create different levels in your garden. Always use glass sanding tools to bevel the edges of your creations after you cut them. Cut glass is extremely sharp and requires no more than a touch to cut you. Also, wear thick gloves while handling cut glass.
Draw a line around your jar where you want to cut it. Use a wax pencil; it will stick to the glass, unlike chalk, but can be cleaned away later, unlike permanent marker. Use masking tape to make sure your line is straight.
Cut a length of string long enough to wrap around your jar with some extra. Dip the string into some kerosene and squeeze it out until it no longer drips.
Fill a large plastic container with very cold water. Make sure the container is deep enough to immerse the whole jar along with most of your arm. Put on your rubber gloves.
Tie the string tightly around the line on your jar, using a double knot instead of a bow. Light one end of the string on fire with a match; make sure the jar is sitting on a non-flammable surface. The flame should circle the jar very quickly.
Plunge the jar into the cold water immediately after the flame goes out. Hit the glass jar above the line as sharply as you can. The glass should break cleanly at the line. Remove the jar from the water, let it air dry and bevel the edges.