I'll give you some techniques an practices that I use. I am currently going to school for acting. Hope these help in some way!
For diction:(speak out loud 3 times in a row)
The lips, the teeth, the tip of the tongue
Unique New York
The big black bear bit the big black bug and big black bear bleed black bear blood
Will you won't you, will you won't you, will you won't you, join the dance, ("Wont you will you" repeated similar to the first phrase)
kitty wants a corner (Theatre game)
Breathing techniques (very important)
The question game( always asking a question, whoever doesn't answer in a question loses)
Hope some of these help. Get some friends to join with you. They are fun games to play! Good luck!