Ming (Agents of Speech) outlines main routes for teaching nonverbal children: AAC/picture-exchange systems, naturalistic/follow-the-child approaches, and more structured ABA-style methods. Ming reports using a mixed approach but leaning toward structured methods and advises parents that structure is important because unstructured attempts can overwhelm caregivers and be hard to implement.
Chapters
Here are some speech therapy techniques for nonverbal children that we use at Agents of Speech to teach parents. The first thing that you have to think in your mind is that what route do you want to take when teaching your nonverbal kid? There are loads of ways that you can go. You can go with the AAC route, meaning using picture exchange systems. The second one is like being very naturalistic, following the child's lead. Loads of therapists on the Internet are doing that, are teaching parents to do that as well. Then we have the more structured camp, which is within the realms of like aba. For me, I use kind of like a mixed approach for all of these and I tend to lean more on the structured. If you're a parent, you're watching this, you need structure or else. A lot of times when you're trying, brain cannot handle so many things going on. You might think, oh, it's just playing with kids. But when you really do try, it's actually quite hard.