The first method of ice pack making is ridiculously simple. Simply open a zip top bag of your choosing, fill it 3/4 full with dish soap, squeeze our remaining air and seal before freezing. This method will allow you to make all shapes and sizes of packs for bumps and bruises of different sizes.
(Note: Make sure to use a soap that doesn't resemble foods you normally keep on hand.)
Check out Tip Nut for the other two methods of Ice Pack making. One involves Vodka and the other Rubbing alcohol, both should make a nice on-hand pack for the occasional bump into your furniture.