How to keep my voice under control?

this isnt a singing question, its just sometimes when i talk i get random cracks. i want a strong, elegant voice, kept under control. like rukia *if u watch the anime Bleach you'll understand. I aslo tend to talk and laff a bit loud, i dont mean too but it happens naturally. is there anyway i can control my voice better and stop the random cracks *it gets kinda embarrassing. Thank you