Researching spelling bees will get you acquainted with the competition process. Reviewing movies like "Akeelah and the Bee" and watching videos of previous bees will help you know what to expect. It would be very advantageous to review past competitions of the bee you are preparing for. Note the questions contestants ask and how many times they repeat the word. You may be allowed to ask the meaning of the word and the root meanings. The speller uses this information as clues about how to spell the word. Sometimes there is a specific routine used during the competition. It could go something like this: say the word, spell the word and say the word again. Use your research to get you ready for a winning competition.
Practice makes perfect. That's certainly true when it comes to mastering the art of spelling. To get an accurate inventory of spelling words in your memory you'll need to do some drills. And then when you think you are ready, drill some more. Drills are done by creating lists of 10 or 20 spelling words. With a partner, you take turns spelling the words. Use highlighter markers and pencils to mark the ones you missed the first time around. Study the roots of the missed words to learn the meanings. This could help you in the spelling bee. Use paperback dictionaries or lists of words from previous competitions. Visit websites that have drills you can use for free.
Spelling games like Scrabble and UpWords are perfect for spelling practices. Invite friends over or call on siblings to help you prepare by playing some games. You could also ask your family to help you set up a mock spelling bee game. Let them choose about 50 words randomly from the dictionary. They could write them on blank index cards. Let them call out the words individually and have you spell the words back to them. They should put aside any words you miss. Study those words later. Don't be discouraged if you miss a few. It's just practice. It's the real spelling bee that counts.