Here is the sample of easy tongue twister.
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?
Say those word quicker and quicker and feel the pronunciation and word connection.
Here is the sample of medium level of tongue twister.
Betty - bought - some - butter - but - the - butter - Betty - bought - was - bitter - so - Betty - bought - some - better - butter - and - the - better - butter - Betty - bought - was - better - than - the - bitter - butter - Betty - bought - before!
Another
example I collected from many sites (download-esl.com/tonguetwisters/
& learnenglishkids.britishcouncil.org/en/tongue-twisters):
"If two witches were watching two watches, which witch would watch which watch?""How much wood would a woodchuck chuck if a woodchuck could chuck wood"
"Can you can a can as a canner can can a can?"
"When you write copy you have the right to copyright the copy you write."
"Eleven owls licked eleven little liquorice lollipops."