Keep the jar on your altar if . . .

. . . your goal is an ongoing one that you’d like to keep working on. You can continue to burn candles over the mouth of the jar or shake it while saying your chant to keep it working for you.

Alternatively, if you have a shrine to your God/dess and sought their aid, you can keep it there. Again, shake it occasionally while chanting to keep the power going.

This is actually a good option for spells that are going to require a great deal of time and effort—for example, if you were to do a jar spell to help you pass tests, you might keep it on your altar all through college. You might repeat your chant, burn a candle or shake it the night before exams. This is better than making a new spell for every exam.

Dismantle the jar if . . .

. . . the spell's power is no longer necessary and you’d like the effects to stop. For example, if you cast a jar spell to attract love, you might have had many interests for a while. Now, you are getting married and you don’t want to attract any more potential lovers. So you would dismantle the spell.

To do this, remove the contents and bury them at a crossroads or into running water, clean the container and dispose of it. With a proper cleansing, you could re-use it.

Warning: It’s not generally a good idea to dismantle a jar used for cursing or hexing, or one for breaking a curse or hex, unless you really know what you’re doing. Just bury it at the crossroads or in running water and be done with it.

Do Not Burn Your Spell Jar

One thing I do not recommend is throwing it into a fire, as is mentioned in some sources. This was, in particular, a method of cursing and curse-breaking; the Witch would throw the jar into the fire and when it burst, it meant the curse was working (torturing the person it is cast on) or it meant the curse you were lifting has broken.

This is not necessary, and not a safe option at all. However, if you do dismantle a jar spell and have some components left over (ribbon, paper, etc.), you could burn those items after it’s dismantled if you have a safe means of doing so.