It is, indeed, the undisciplined, random approach many students use in their own checking processes that leads to so few errors and mistakes being corrected before the teacher sets the red pen loose. Students are invited to read their scripts four times, identifying and highlighting specific areas for attention. These areas, I must emphasise, are not universal and would be decided by the teacher according to how he or she sees the needs of the class. Some faults, however, are endemic. A four-step approach 1.
Students read their scripts for the first time and draw a circle around each verb.
In my experience the method of using geometrical shapes to highlight makes it easier to focus on and remember potential problem areas than mere underlining. The questions asked would be supplied by the teacher, again depending on common errors or mistakes found. Ask yourself whether the verb is in the right tense, given the situation and what has been said before and afterwards. Ask yourself whether the word order after the verb circled is correct or not. The result of each check, particularly at the beginning of training, is inevitably more doubts raised than words and expressions corrected.