How do I improve my English speaking?

Hi, this is Teppei.

Few days ago I went out with my wife and her friend Julia.

She is teaching English at some schools.

Because of my work, I sometime to facilitate in English for natives about the leadership and some other business skills.

So far I don't have any serious issues in speaking English but I am not sure which level I have right now.

I have done the workshop for the organizations in English and received good feedbacks from natives.

I provides the skills and tools for them. After the class all participants are equipped to benefits their works.

The contents and tools are very helpful for them but I always wonder my expressions are right or not.

Now so far nobody give us the feedback.

So I made up my mind to join the Toast master club to improve my English.

Do you know any other ways to improve your English?