If you, or your children, need to work on your enunciation, tongue twisters are a fun way to improve! When you start getting good, put a pencil between your front teeth and try again. If you master that, use marbles like Audrey Hepburn in My Fair Lady. Also like Ms. Hepburn, I would caution you to be careful not to swallow. ;-)
Here is a great website...1st International Collection of Tongue Twisters, you have to choose what language, and there are over 400 in English!
I did this with my children, some had lazy speech patterns. This helped immensely. I also have a daughter who performs, and has aced auditions because she does not trip over her words when she speaks. She is a nearly flawless tongue twister, reigning champion in our home...she unseated me in that title!