The teaching strategy that I use most often with my students is to incorporate their interests into the lessons and learning activities that I plan for them.
Activities that are inherently difficult, such as language-based activities, can be much more motivating and interesting if the task is about a favorite character, animal, subject, etc.
I was recently working with one of my students who loves ocean animals. He enjoys making these "sticker art" pictures, so I use it as an opportunity to work on language. After he makes a picture, I ask him questions about the picture (from the book "Visualizing and Verbalizing"). Since he's familiar with how to answer these questions, we then use this information to write a paragraph describing the animal.
Once the student has answered these questions (with support/prompting as necessary), I help the student take this information and write it into sentences.
Here's another example:
If your student isn't quite ready for writing paragraphs, you can start by having the child describe the picture in one word ("octopus") or a short phrase, such as "blue octopus" or "small red crab." Once the child can describe pictures with short phrases, you can work on a single sentence. Then, move on to answering multiple questions to write a short paragraph.
For information on how to prompt students to give the correct answers to these questions, please review the resources listed below. Prompts and prompt fading are some of the most common teaching approaches that I use, so these blog posts are definitely worth the read! I also always recommend getting training on these skills from a Board Certified Behavior Analyst® (BCBA®).
How to Use Prompts Effectively and Efficiently: https://theautismhelper.com/use-prompts-effectively-efficiently/
Procedures for Prompt Fading: https://theautismhelper.com/procedures-prompt-fading/
Here are the books mentioned in this blog post: