Some great advice there for you!

We have a time out corner. I like the term thinking spot thought.
A few suggestions: you can role play with teddy first. So teddy does something that isn't allowed and then has to go and stay on the naughty mat.

Our time out corner is used the first time DS1 does something not allowed - no warnings if he knows that it is not allowed behaviour. Also, we always make him say sorry (in sign as he can't say it yet) when time out is up. And we remind him not to do the behaviour again. And we always say we forgive you and we love you when he gets out of the time out corner.

Good luck!