What is the best way to teach the skill of speaking?

Speaking is practice...if we reside it continue you are used to it. More important you need to learn or teach it with audio visual means makes it easier to gain.

The best way to practice a skill in any language is to be observant and to be able to listen with much attention in speaking and listening you may not.only observe the proper grammar itself but must be with action so people can understand and relate what is being delivered.

Best pronunication and habitual way to speak in all time in every minute of life , is the best way

when my students watches  more and real and nutral video 

when they practice short and open diyaloge