There are two primary ways to fix a fragment:
(1) First, you can rewrite it so that it contains its missing pieces: a subject, a verb, an object, or a combination of the three.
Dropped an antique vase + subject = Jerry dropped an antique vase.
By adding a subject, Jerry, we've made this a complete sentence. Jerry, you menace to society.
I sent + object = I sent a package.
Since "I sent" by itself isn't a complete sentence, add an object—in this case, the direct object: a package. You can even take it further and add an indirect object, Mary: "I sent a package to Mary." or "I sent Mary a package." Go nuts, Shmooper—it's your sentence.
(2) Second, you can correct a fragment by joining it to a nearby complete sentence.
After the football game. + We grabbed a pizza at Gino's.
After the football game, we grabbed a pizza at Gino's.
Attaching a fragment to a neighboring sentence is a pretty solid way to fix fragments. As you can see from this example, fragments are often found in dependent clauses. These fragments generally start with a subordinating conjunction like because, although, if, or—like we have here—after.
To fix them, just take that dependent clause and hook it up with the independent clause that comes before or after it. Easy, right?