Before each important meeting or in the morning, I work my diction. Tongue twisters that I learned from my theater classes are really helpful. We usually do it in almost all classes and also before a play. This way, we are sure that our muscles are relaxed, and the audience will understand us perfectly.
I put in practice those exercise in my consulting routine because I consider it fundamental to be speaking clearly.
Here are some examples of tongue twisters:
She sees cheese.
How can a clam cram in a clean cream can?
I scream, you scream, we all scream for icecream!
Seventy seven benevolent elephants
Peter Piper picked a peck of pickled peppers.
A peck of pickled peppers Peter Piper picked.
If Peter Piper picked a peck of pickled peppers,
Where’s the peck of pickled peppers Peter Piper picked?
More examples here: