First and foremost you should hire a professional fire juggler/swallower, make sure to do your due diligence online before you hire this person. In this day and age everyone has a website or at least a facebook fan page which you can use to find out a bit about the performer you wish to hire.
He should tell you all the requirements that is necessary. He/She should let you know that he needs a area clear to himself. A place that is somewhat sectioned off so that no drunk people can walk into his area while he is performing.You should have a fire extinguisher and/or a bucket of water handy.
I feel as though many of you who are reading this post will actually want to fire juggle.
Step 1; Do not attempt to do any fire swallowing stunts, you need proper training to do so and if you have the proper training then you will not be reading this post.
Step2; Learn how to juggle with clubs that are not on fire and learn how to do it at night. You need to do it so wel that it becomes second nature, the only way to do that is practice, practice and more practice.
Step3; Get Some high quality flame retardant clothing.
Step4; Go somewhere safe to practice.
Step5; Utilize a bucket for your fuel, it is much easier to dip your torches rather then squirting fuel on them. Have a lid for your fuel bucket.
Step6; Safety, have a bucket of water, a fire extinguisher and be mindful of your surroundings.
Step7; Shake off excess fuel, give them a good shake aiming at the ground so that you do not spray fuel every where.
Step8; Light One torch at a time.
Step10; If you fumble a catch whilst juggling just let the torch fall, there is no point risking getting your hand burned.
Once you have this mastered it makes for quite a dazzling display at night, or even an added element of danger and excitement to a day time juggling show. As always exercise extreme caution when doing these stunts!