I have often been required to have students write beyond their actual level. The fastest way I’ve found to get them from where they are to where you are required to take them is to provide scaffolded writing prompts. The level of scaffolding will depend on their level and the level of writing expected.

For your lowest-level students, this will look a lot like MadLibs. You provide the bulk of the text and have your students make additions from choices you also provide. For test prep or more academic writing, you can provide example test essays with connectors and hedges removed, so they can practice using those correctly. For a greater challenge, you could provide the first sentence of each paragraph in an essay, and have the students complete the essay.

For a greater challenge, you could provide the first sentence of each paragraph in an essay, and have the students complete the essay.
A basic high-beginner scaffolded writing activity I do is give students a journal prompt with a mind map which I have started for them.

Depending on the prompt, I will create several lists on the mind map and fill in at least one example on each list. For example, for a narrative prompt, I may ask them to list five memories related to the topic. After listing five, they will then choose one and answer the basic 5W and H questions about that memory.  I may also include a list of useful words related to the topic.

Students begin by filling in their mind map, then write their journal. This helps them think through what they want to say and helps them create a cohesive, understandable journal entry.

I haven’t used this for poetry writing, but you can read about that here at the Writer’s Corner blog.