I will never forget middle school- studying how to spell everything from "onomatopoeia" to "xylem" to "diarrhea" (which I think I had the night before the contest). Then going to regional and missing "besieged". The trauma! The horror! I felt like i had really let my teacher down.
First thing...don't take it too seriously. You could know almost every word in the language, and still get the one you that you aren't familiar with. Oral spelling bees are a game of odds. A bit like a game show, in that how well you do totally depends on what words you are given to spell.
As far as studying, just do some reading and notice words that you might need to practice. Look for exceptions to spelling rules and words that are easily confused, as in my case when I assumed "besieged" would have the same construct as "seize". You might try googling "most commonly misspelled words". I'm sure your teacher would be able to provide you with a study list. Have someone call the words out to you and concentrate on the ones you miss. If you do miss some, try looking them up- often a word's spelling construction has something to do with the origin of the word. That can help you spell related words. You might consider keeping a little notebook. Jot down any words you consider difficult and look at them or copy them during spare time.
Other than that, have fun. If you aren't stressed, you will generally do better. :)
Oh...and don't stay on EP long. You don't want the spelling errors on here to rub off on you!
Remember the sound of each word, then spell it . I'd been through it and it will be fun for you. Just be calm. Good luck!
Well Blue berries help with the short term memory process so if you eat a bowl of raw Blue berries every time you study you will remember more.
I remember my junior high, school-wide, spelling bee... I was considered a "smart" kid and I still went down on the first word (I don't remember what it was). Not to discourage you, but them not typical words they give ya'!!