things i sometimes forget, in my enthusiasm

WikiHow: How to Communicate With a Non Native English Speaker
Avoid touching your listener. Even if you want to nudge them in the right direction or encourage them with a friendly pat on the back, your gesture may be misinterpreted. Many cultures view personal contact very differently and your friendly touch could be seen as aggressive or overly familiar.

And, no, “avoid touching your listener” is not a euphemism. The rest of the advice on that site is also quite good; I find I follow most of it already when trying to communicate in English here in Japan.