It will depend primarily on the sentence in question.
Watch for the clues listed in your Sentence Correction book under the different question types. For example, on the Verb Form questions, you'll notice several verbs in one sentence, or different versions of the same verb in different answer choices. If you see either of these, you'll want to check the verb tenses, voice, etc.
If, on the other hand, the sentence begins or ends with a modifier, you'll want to verify that the modifier is next to that part of the sentence it really should be modifying.
Review the first part of the Sentence Correction I book, and at the end of each question type description, you'll be given some thing to watch for to recognize each question type.
However, as you have trouble identifying the process in a specific sentence, please post it and we'll help you recognize clues and identify the process necessary to solve the problem.