Pick the right contest. If you're going to rig a spelling bee to make sure you win, it's probably not wise to choose one of the big contests that are televised or receive a lot of attention. These larger competitions are likely to have stricter rules and heavier security, and the possibility that it may be on television will increase your chances of getting caught. Start with a smaller local bee where you will be able to arrange things more easily and with better odds of going undetected.
Research your target. Find out the location of the bee, and look into areas where you might be able to conceal notes or mirrors to help your chances or where someone helping you can be hidden. Know ahead of time how many people will be officiating, if there will be judges at the bee designated to watch for improper activity and how many contestants will be competing.
Know your stuff. One of the best ways to avoid detection is to look like you don't have to rig it at all. Study your words, and utilize one of the many study guides that are available specifically designed to help spelling bee contestants succeed. If you appear as qualified as the other contestants, you will have a better chance of avoiding suspicion.
Befriend a judge. Most local spelling bees will enlist community leaders and teachers to judge the contest so you should be able to "accidentally" run into them ahead of time, and make a good impression. Appear smart, articulate and friendly, but do not give any indication that you know they will be judging the spelling bee.
Get help. Having a second person to help you rig the bee can be the key to success. If you have a floor plan for the facility, pick a place for your helper to sit or stand where you can clearly see them from the stage. Devise a code system for your helper to give you clues or signals from the audience in case you get confused or need help. Have signals for commonly confused vowels or rarely used consonants. Make sure that your assistant can keep cool during the spelling bee and that they can be trusted.
Remain calm and collected. If you feel that you are attracting attention or that someone is suspicious, spell a word wrong on purpose and give up the bee. Do not get flustered or draw attention to yourself. It may be a disappointment, but at least if you lose you can't be accused of cheating in order to win.