Where I get these ideas, I don’t know, but I was on the search for some really good tongue-twisters and I think I’ve found some good ones:

• unique New York
• knapsack straps
• cheap ship trip
• lovely lemon liniment
• Greek grapes
• Peggy Babcock
• flash message
• truly rural
• Pacific Lithograph
• pre-shrunk silk shirts
• please pay promptly
• shredded Swiss cheese
• tragedy strategy
• selfish shellfish
• black bug’s blood
• girl gargoyle, guy gargoyle
• good blood bad blood
• inchworms itching
• mixed biscuits
• Sixish.  Sixish.  Sixish.
• thieves seize skis
• Tim, the thin twin tinsmith
• two toads, totally tired

Try those a few times fast!