Teachers use printable writing paper sheets. They let their students trace the numbers, letters, words or dots as this is the perfect way for a child to practice the controlled movements of his fingers and wrist. With continued practice or tracing, he will soon be able to write more legibly and clearly.
There are many kinds of worksheets available but the best one is still the personally drafted one. This way one can easily check the level of difficulty that is offered to the kids according to their age and even check the progress level. Worksheets can be reused but it is always better to upgrade them from time to time.