Here is another great clarification question from a podcast subscriber about How to say OF:

Oh crap. It’s gonna be very hard to fix it as it’s a common word, I had never noticed the difference.   Feels like the “o” sounds different too.  

Yes, correct.   My videos are too short to get into this, but when OF is used in a phrase, the O is more closed than when just saying the word alone.   This is because vowels in words in phrases become shorter when they are unstressed.

And don’t worry about being exact, you just need to be clear and “close enough”. Remember to focus on the clarity of your message; not perfection.