✏️ Paper first! Work out every question on paper before you open the answer. Write down every step – the equation, the numbers with units, the rearranging and the answer with its unit. In the exam, if your final answer is wrong you can still get marks for correct working, but only if the examiner can see it.
Find the resultant of forces in a line, at right angles and at any angle. Build the parallelogram yourself, split a force into two components, and check every step in the worked solution.