One thing you need to do in situations like this is to get object imitation straight. To improve imitation in children, we want to collect identical items of things. For instance, two little drumsticks, two plastic spoons, two plastic cups, two green napkins.
You’re not going to present all of these things at the same time. The real goal isn’t to target that a child will put the red block in the cup, but that they copy an action. To prevent rote responding you want to have each set of items do two different things.
Now, it sounds like this question came from a listener who has a behavior analyst and they might want to write down targets, like “flip the cup” or “red block in cup” or “tap red block two times.” That’s fine. But if the child can put a bigger red block in, they should be able to put a yellow block in.
This should be a fun program and should not involve crying or upset. If they need, you can maybe use less materials.