It can be done from both input and output.

Output part: You can train them to form the habit of writing every day, such as keeping a diary, such as writing some subject words. So as to improve writing ability.

Input part: reading some novels, compositions and other materials is helpful to form plot ideas and expand imagination, thus paving the way for designing the plot of a novel or sending it to the plot level.

The fourth grade is still young and needs to be gradual.