Freestanding cabinets provide an extra space so that you can keep all the important things at one place. When the cabinets in the kitchen are not sufficient people go with this option as you can easily keep it on the floor or mount it on the wall too. But to fix the cabinet you need a space in the wall so that it does not look occupied and filled. The fixture has to be strong enough so that it can hold the pressure when the jars or bottles are kept inside.
You can do the fixing on your own. Mark the position where you would like to place the cabinet. With the help of drilling machines screw the cabinet in to the wall and tighten all the screws and studs that are supported for it. In case you find it difficult you can ask a carpenter to help you but on the whole it will be good and affordable.