Some Conjunctions (joining two independent phrases)
The beginnings of some sentences (eg. meanwhile, tomorrow,)
There can be over-usage of commas. What you are talking about (the natural pauses?) is called a caesura, which comes from Caeser, who was a great speech giver. Caesura means the pauses we naturally include when speaking. While it's a pretty good rule-of-thumb to insert a comma when one pauses, that is not always the case...
Also I sent you a PM and a visitor message to ask you what the heck you wanted to talk to me about but honestly tourism doesn't interest me.
I will be selling the intermediate-expert levels of lessons. The beginner lessons will be free and hopefully draw in traffic. Thank you for your comments.