Rachel's English
American English - UH [ʌ] Vowel - How to make the UH Vowel
Rachel has a background in classical singing, and she brings her expertise of voice and pronunciation to all of her videos. If you’re looking to “reduce” your accent or refine your pronunciation, Rachel’s English is a great place to start.
ESLbasics
Tongue Twister - Woodchuck
This YouTube Channel has mini-lessons on vocabulary, idioms, and phrasal verbs, this channel is perfect for learning vocabulary quickly. This video playlist contains tongue twisters from Andrea Giordano to help you practice your pronunciation. The first one is the tongue twister entitled, "How Much Wood Could a Woodchuck Chuck".
How to improve your English speaking - Learn English Live 18 with Steve Ford
This video channel has English lessons from basic to fluency levels. You can use these channel to help you with TOEFL, studying business English, or improving your conversation skills. The playlist is Steve Ford's 19 most popular videos. In the first video on this list he answers questions from his students.