If you have problems with recvognizing fragments in your own writing, look for these patterns in your work.  Pay attention to how these look, and pay attention to how these sound.
 

What it looks like—

What it is—

Somebody. Something. Something from something else. Somebody doing something. Doing something. And doing something. And did something. And has done something. To do something. Such as something, something, and something else. When somebody does something. Because something happened. Something that happens. Something that somebody did something to. Somebody who does something. Which does something. That somebody does something to.

A noun by itself. A noun by itself. A noun with a prepositional phrase modifier. A noun with a participle phrase. A participle phrase or a gerund phrase by itself. Half a compound participle phrase or gerund phrase. Half a compound verb in the past tense. Half a compound verb in the present perfect tense. An infinitive phrase by itself. A list of examples by itself. An adverb clause by itself. An adverb clause by itself. A noun with an adjective clause. A noun with an adjective clause. A noun with an adjective clause. An adjective clause by itself. An adjective clause by itself.