Mike's advice is dead on.
Fruit beers (or spice/herb/veg, or any other non-standard ingredient beers like wood aged, etc, as this applies to ALL non-base styles) should start with a really good base beer. The base beer should be good enough to medal on its own. Adding the specialty stuff should enhance the overall beer, but you should still be able to taste the underlying beer. I've had (as has Mike and Jim as well, as both are BJCP judges) many such specialty beers where either the special ingredient gets lost or it overwhelms everything else.
It should be notable but not overwhelming, the whole should be greater than the parts, the parts should not clash in any way, but rather harmonize. After looking for the requisite properly fermented beer that meets the style, balance is the key that the judges will be looking for to separate the good ones from the great ones.
Hope this helps & GOOD LUCK! Comps are a fun way to help you gain feedback and experience. It helps make your beers get better and better-