Pittsburghese and Diphthong “ow”
Where I come from in Pittsburgh Pennsylvania, there is a regional accent called Pittsburghese. Many Pittsburghers are known for their regional accent and many people perceive it negatively. Here is a tip for just one of the components of Pittsburghese.
Pittsburghese contains the mispronunciation of the diphthong “ow.” A diphthong is actually two vowels put together. In the case of “ow” the two vowels are “ah” and “o.” With Pittsburghese, only the first vowel “ah” is said so that words with the sound “ow” sound like in house, and downtown sound like “dahn tahn” (down town), and “hahs” (house).
Maybe you are uncertain if you mispronounce this sound. Luckily, there are some visual cues to look for. Watch yourself in the mirror as you say “cow” to see if your lips round at the end for the “ow” vowel. If not, you are only saying the first part of the sound.
To correct this error, one must learn to connect the two vowels together. Say the two vowels separately with a clear break between the two sounds.
Ah=>o. Next, say them very slowly connecting them together. Once you have successfully put them together slowly, try speeding it up a little bit. Remember to watch yourself in the mirror to get some visible feedback.
Eliminating a regional accent can help you obtain a new job or that promotion because clear communication is an essential part of an executive’s role.

Comments
But it doesn't work in every situation and employers often don't like the image/brand it projects with their executives.
Thanks for the comment!
On the other hand, I recently listened to a speaker who had such a strong southern accent that it was obvious she came from so far south of the Mason-Dixon line that she can see the equator from her house. Yet she made no attempt to subdue her accent. In fact, she made the most of it, mint julep dripping from every syllable. And the audience loved her.