The benefits of tongue twisters:
Regardless of the language that you are using or in the process of learning, I highly recommend the use of tongue twisters (in that particular language) for better articulation. In other words, it is beneficial for language learners as well as native speakers. It is also an activity that drama students use too to improve on their articulation skills.
You can use them any time of the day. However, I particularly recommend this articulation improving exercise in the mornings so that you can speak clearly during the day.
In addition, I strongly recommend tongue twisters if you are trying to learn to touch type (typing with your ten fingers without using the sense of sight to find the keys). Just type up some tongue twisters until competent.