You'll need: a bolt snap, line, scissors, a lighter, and the object to which you'll attach the bolt snap.
Cut a length of cave line a couple of feet long. Run it through the eye of the bolt snap, then run each end of the line through the object's hole in opposite directions. (If the object is a hose, then just wrap each end around the hose.)
Run each end of the line through the eye of the bolt snap (in opposite directions).
Snug up the line to allow the desired distance between the bolt snap and the object. Tie an overhand knot so that it rests against the bolt snap.
Turn the whole assembly over, so you're looking at the other side. Tie an overhand knot, tight enough to encircle and snug up the lines running between the bolt snap and the object. Tie a second overhand knot (the reverse of the last one) to form a square knot. Pull it very tight.
Trim each end of the line, leaving about 1/4-inch free.
Use the lighter to melt one of the free ends of the line, which will ball up into a shape roughly resembling a mushroom cap. Keep the heat of the flame away from the object. You want to melt the end of the line and nothing else. Be very careful to avoid touching the molten nylon, and don't let it drip on you. Molten nylon can cause a very painful burn!
Mash down the molten nylon (using the blunt end of the lighter works well), flattening it out and preventing the ends from slipping back through the knot. Blow on the molten nylon until cool. Repeat steps #7 and #8 with the other free end of the line.
Carefully examine the finished product. Twist it. Pull on it. Look for any sign of weakness, and if you find one, cut the knot off, and start over from the beginning.
