Teach Letters With Fish
Trying to teach kids when they are not paying attention is the number one issue I see with toddlers on the autism spectrum. I see it in the classroom environment, therapy clinics, and in the home. This is a serious issue, and in most environments parents don't have any control over what's going on. At home, it's a different story. You can overcome attention issues by playing with your kid. Use the kid's inherent motivations and likes to get them engaged in activities where you can target specific skills and language.
Matching activities are a great way to build vocabulary for children with autism because they only require early visual skills to be successful. Matching activities also benefit from being really intuitive in nature. When presented with identical items they're interested in, kids will often match them on their own. This means you don't have to provide a ton of language-heavy direction to kids who have severe delays in their language and social skills. Instead, you have ample opportunities to model language and skills while the kids are engaged with the matching activity.