How would a Vietnamese learner of English practice English if he lives in Vietnam and everybody around him speaks Vietnamese? In this context, practicing English speaking skills is a tremendous task.
You might say, hey, find someone who speaks English and practice with that person. You are right but sometimes that is impossible. More than that, many people find speaking English with friends very ridiculous; many people try then five minutes later they switch back to their own language.
Then what is to be done? Simple, speak English to yourself!
Speak English to yourself in front of the mirror. Try to make a conversation in English with yourself, you ask and you answer. Imagine what you would like to talk to someone who you just met, or pick up a dialogue from your favorite movie and practice it. The possibilities are endless. My neighbor does it every day and it works, it works so well.
Practicing your English speaking skills this way comes with many advantages but the one I see it as the biggest advantage is that you don’t depend on anyone and anything. You can do it at home everyday, anytime, and how you want.