Even if your work is top-of-the-line and everyone else says so, take time to consider, before entering a contest that asks a $20 or $25 fee (those add up), who the judge is. Most of the time the entity holding the competition is pleased to announce the names of its judge or judges, who are often well-known.
This is a great opportunity for you because the best way to gauge your work's chances of winning or placing in a contest likely to have 400 to 1200 contestants is to look up the work of the judge. If he writes "masculine" hunting and fishing stories he probably likes reading them, and if your story is about a sewing circle, the odds of its winning are not very good. Or if his poetry is super avant-garde and yours is traditional, you won't win no matter how good your submission is. When you and the judge share the same literary values your chances are much better.
So Google your judge before submitting. It's one way to be sane about the nagging question "Should I enter?"
There are other factors involved that a contest entrant cannot correct for, including the people who do the initial screening. But the "check-out-the-judge" approach saves you entry fees for contests you are unlikely to win. We writers are very lucky that literary contests change judges every year. Maybe next year that juicy prize will be within your grasp.