Always stress the importance of reading the test questions carefully. A lot of children, because they think they will run out of time, just quickly skim through the questions and then end up misinterpreting them, making unnecessary mistakes. Explain to the children they surely have enough time to slowly read the question and encourage them to read the questions twice or three times until they understand the question in its full. Present the children with examples of tricky questions, like for example double negatory questions, so they will understand the importance of not rushing through the test.
When solving multiple choice questions, recognizing the wrong answers is just as important as recognizing the correct one. Practice multiple choice tests with children. Make the questions difficult, but make the wrong answers obvious so that children will easily single them out. Also practice questions that offer more or no answers at all. A combination of questions like these can be confusing, so children should practice them to understand the logic behind tackling tests like these.
Make it clear to your kids that they should never spend too much time on a question they don't know how to answer. Encourage them to finish everything they know and then go back and try to answer the questions they had problems with and couldn't figure out the first time around. Spending too much time on a single question might cause the kids to run out of time at the end or make them panic, disturbing their concentration.
Give the children an assignment in which you ask them to make their own tests. The tests should include questions that require explanation as well as multiple choice questions. The children should also create a grading and scoring system for their tests. When they bring the test to school, their schoolmates should try to tackle the test and then explain what was good about it and what was bad.